diff --git a/org.eclipse.mylyn.commons.repositories.core/src/org/eclipse/mylyn/internal/commons/repositories/core/SecureCredentialsStore.java b/org.eclipse.mylyn.commons.repositories.core/src/org/eclipse/mylyn/internal/commons/repositories/core/SecureCredentialsStore.java
index 8be852d..956b0ee 100644
--- a/org.eclipse.mylyn.commons.repositories.core/src/org/eclipse/mylyn/internal/commons/repositories/core/SecureCredentialsStore.java
+++ b/org.eclipse.mylyn.commons.repositories.core/src/org/eclipse/mylyn/internal/commons/repositories/core/SecureCredentialsStore.java
@@ -176,11 +176,15 @@
 	}
 
 	protected ISecurePreferences getSecurePreferences() {
-		ISecurePreferences securePreferences = SecurePreferencesFactory.getDefault().node(ID_NODE);
+		ISecurePreferences securePreferences = openSecurePreferences().node(ID_NODE);
 		securePreferences = securePreferences.node(EncodingUtils.encodeSlashes(getId()));
 		return securePreferences;
 	}
 
+	protected ISecurePreferences openSecurePreferences() {
+		return SecurePreferencesFactory.getDefault();
+	}
+
 	private void handle(StorageException e) {
 		if (!loggedStorageException) {
 			loggedStorageException = true;
diff --git a/org.eclipse.mylyn.commons.repositories.tests/src/org/eclipse/mylyn/commons/repositories/tests/core/SecureCredentialsStoreTest.java b/org.eclipse.mylyn.commons.repositories.tests/src/org/eclipse/mylyn/commons/repositories/tests/core/SecureCredentialsStoreTest.java
index aae921b..265cf13 100644
--- a/org.eclipse.mylyn.commons.repositories.tests/src/org/eclipse/mylyn/commons/repositories/tests/core/SecureCredentialsStoreTest.java
+++ b/org.eclipse.mylyn.commons.repositories.tests/src/org/eclipse/mylyn/commons/repositories/tests/core/SecureCredentialsStoreTest.java
@@ -12,14 +12,23 @@
 package org.eclipse.mylyn.commons.repositories.tests.core;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 import java.util.Arrays;
 
+import org.eclipse.core.runtime.AssertionFailedException;
 import org.eclipse.equinox.security.storage.ISecurePreferences;
 import org.eclipse.equinox.security.storage.StorageException;
 import org.eclipse.mylyn.commons.repositories.tests.support.DelegatingSecurePreferences;
 import org.eclipse.mylyn.internal.commons.repositories.core.InMemoryCredentialsStore;
 import org.eclipse.mylyn.internal.commons.repositories.core.SecureCredentialsStore;
+import org.eclipse.mylyn.internal.commons.repositories.ui.UiLocationService;
+import org.eclipse.mylyn.internal.commons.repositories.ui.UiSecureCredentialsStore;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.ui.PlatformUI;
 import org.junit.Test;
 
 /**
@@ -27,10 +36,14 @@
  */
 public class SecureCredentialsStoreTest extends AbstractCredentialsStoreTest {
 
-	private class StubSecureCredentialsStore extends SecureCredentialsStore {
+	private class StubSecureCredentialsStore extends UiSecureCredentialsStore {
 
 		DelegatingSecurePreferences delegate;
 
+		private boolean openSecurePreferencesCalled;
+
+		private Display display;
+
 		public StubSecureCredentialsStore() {
 			super(SecureCredentialsStore.class.getName());
 		}
@@ -59,6 +72,20 @@
 			return super.getInMemoryStore();
 		}
 
+		@Override
+		protected ISecurePreferences openSecurePreferences() {
+			openSecurePreferencesCalled = true;
+			display = Display.getCurrent();
+			return super.openSecurePreferences();
+		}
+
+		protected boolean wasOpenSecurePreferencesCalled() {
+			return openSecurePreferencesCalled;
+		}
+
+		protected Display getDisplay() {
+			return display;
+		}
 	}
 
 	@Test
@@ -138,4 +165,71 @@
 		assertEquals("value", store.get("key", null));
 	}
 
+	@Test
+	public void testopenSecurePreferencesThrowsExceptionOnUiThread() throws Exception {
+		runOnUiThread(new Runnable() {
+			public void run() {
+				assertNotNull(Display.getCurrent());
+				StubSecureCredentialsStore store = new StubSecureCredentialsStore();
+				try {
+					store.openSecurePreferences();
+				} catch (AssertionFailedException e) {// expected
+					return;
+				}
+				assertTrue(false);
+			}
+		});
+	}
+
+	@Test
+	public void testAccessSecureStoreOnUiThread() throws Exception {
+		runOnUiThread(new Runnable() {
+			public void run() {
+				assertNotNull(Display.getCurrent());
+				StubSecureCredentialsStore store = new StubSecureCredentialsStore();
+				assertFalse(store.wasOpenSecurePreferencesCalled());
+				store.put("key", "value", false);
+				assertEquals("value", store.get("key", null));
+				// check that openSecurePreferences was called but not from the UI thread
+				assertTrue(store.wasOpenSecurePreferencesCalled());
+				assertNull(store.getDisplay());
+			}
+		});
+	}
+
+	protected void runOnUiThread(final Runnable runnable) throws AssertionError {
+		final AssertionError assertionError[] = new AssertionError[1];
+		PlatformUI.getWorkbench().getDisplay().syncExec(new Runnable() {
+			public void run() {
+				try {
+					runnable.run();
+				} catch (AssertionError e) {
+					assertionError[0] = e;
+				}
+
+			}
+		});
+		if (assertionError[0] != null) {
+			throw assertionError[0];
+		}
+	}
+
+	@Test
+	public void testRunOnUiThread() throws Exception {
+		try {
+			runOnUiThread(new Runnable() {
+				public void run() {
+					assertTrue(false);
+				}
+			});
+		} catch (AssertionError e) {// expected
+			return;
+		}
+		assertTrue(false);
+	}
+
+	@Test
+	public void testUiLocationService() throws Exception {
+		assertTrue(new UiLocationService().getCredentialsStore("test") instanceof UiSecureCredentialsStore);
+	}
 }
diff --git a/org.eclipse.mylyn.commons.repositories.ui/META-INF/MANIFEST.MF b/org.eclipse.mylyn.commons.repositories.ui/META-INF/MANIFEST.MF
index 95e82e4..95672ff 100644
--- a/org.eclipse.mylyn.commons.repositories.ui/META-INF/MANIFEST.MF
+++ b/org.eclipse.mylyn.commons.repositories.ui/META-INF/MANIFEST.MF
@@ -17,7 +17,8 @@
  org.eclipse.mylyn.commons.core;bundle-version="3.8.0",
  org.eclipse.mylyn.commons.repositories.core;bundle-version="1.0.0",
  org.eclipse.mylyn.commons.ui;bundle-version="3.8.0",
- org.eclipse.mylyn.commons.workbench;bundle-version="3.8.0"
+ org.eclipse.mylyn.commons.workbench;bundle-version="3.8.0",
+ org.eclipse.equinox.security
 Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 Bundle-ActivationPolicy: lazy
 Export-Package: org.eclipse.mylyn.commons.repositories.ui;x-internal:=true,
diff --git a/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiLocationService.java b/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiLocationService.java
index f253bcf..ed2bfa1 100644
--- a/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiLocationService.java
+++ b/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiLocationService.java
@@ -25,7 +25,6 @@
 import org.eclipse.mylyn.commons.repositories.core.auth.AuthenticationRequest;
 import org.eclipse.mylyn.commons.repositories.core.auth.AuthenticationType;
 import org.eclipse.mylyn.commons.repositories.core.auth.ICredentialsStore;
-import org.eclipse.mylyn.internal.commons.repositories.core.SecureCredentialsStore;
 import org.eclipse.mylyn.internal.commons.repositories.ui.auth.RepositoryAuthenticator;
 
 /**
@@ -38,7 +37,7 @@
 
 	public ICredentialsStore getCredentialsStore(String id) {
 		Assert.isNotNull(id);
-		return new SecureCredentialsStore(id);
+		return new UiSecureCredentialsStore(id);
 	}
 
 	public Proxy getProxyForHost(String host, String proxyType) {
diff --git a/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiSecureCredentialsStore.java b/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiSecureCredentialsStore.java
new file mode 100644
index 0000000..8f002a6
--- /dev/null
+++ b/org.eclipse.mylyn.commons.repositories.ui/src/org/eclipse/mylyn/internal/commons/repositories/ui/UiSecureCredentialsStore.java
@@ -0,0 +1,71 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.commons.repositories.ui;
+
+import java.lang.reflect.InvocationTargetException;
+
+import org.eclipse.core.runtime.Assert;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.equinox.security.storage.ISecurePreferences;
+import org.eclipse.jface.operation.IRunnableWithProgress;
+import org.eclipse.jface.operation.ModalContext;
+import org.eclipse.mylyn.internal.commons.repositories.core.SecureCredentialsStore;
+import org.eclipse.swt.widgets.Display;
+
+/**
+ * When this class is accessed on the UI thread, access to the secure store will occur on a background thread and the
+ * event loop will continue to run. This prevents a deadlock that can occur when accessing the secure store on the UI
+ * thread.
+ * <p>
+ * Clients should be extremely careful when accessing this class on the UI thread while holding onto a lock (such as
+ * from within synchronized methods). It is possible that the event loop will process an event that spawns another job
+ * (such as when the user opens a dialog which runs a background operation). If that job also tries to acquire the lock,
+ * there will be a deadlock. For this reason, clients should never hold a lock while accessing this class on the UI
+ * thread, unless they can be certain that nothing can cause the UI thread to wait for another job that attempts to
+ * acquire the lock.
+ * 
+ * @author Sam Davis
+ */
+public class UiSecureCredentialsStore extends SecureCredentialsStore {
+
+	public UiSecureCredentialsStore(String id) {
+		super(id);
+	}
+
+	@Override
+	protected ISecurePreferences getSecurePreferences() {
+		if (Display.getCurrent() != null) {
+			// ensure we don't open the secure preferences on the UI thread as this can cause deadlock
+			final ISecurePreferences securePreferences[] = new ISecurePreferences[1];
+			try {
+				ModalContext.run(new IRunnableWithProgress() {
+					public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
+						securePreferences[0] = UiSecureCredentialsStore.super.getSecurePreferences();
+					}
+				}, true, new NullProgressMonitor(), Display.getCurrent());
+			} catch (InvocationTargetException e) {
+				throw new RuntimeException(e);
+			} catch (InterruptedException e) {
+				throw new RuntimeException(e);
+			}
+			return securePreferences[0];
+		}
+		return super.getSecurePreferences();
+	}
+
+	@Override
+	protected ISecurePreferences openSecurePreferences() {
+		Assert.isTrue(Display.getCurrent() == null);
+		return super.openSecurePreferences();
+	}
+}