diff --git a/public/app/features/alerting/unified/Silences.test.tsx b/public/app/features/alerting/unified/Silences.test.tsx
index 204ed9f9bbd..a0e6303c1e3 100644
--- a/public/app/features/alerting/unified/Silences.test.tsx
+++ b/public/app/features/alerting/unified/Silences.test.tsx
@@ -304,6 +304,14 @@ describe('Silence create/edit', () => {
     TEST_TIMEOUT
   );
 
+  it('works when previewing alerts with spaces in label name', async () => {
+    renderSilences(`${baseUrlPath}?alertmanager=${GRAFANA_RULES_SOURCE_NAME}`);
+
+    await enterSilenceLabel(0, 'label with spaces', MatcherOperator.equal, 'value with spaces');
+
+    expect((await screen.findAllByTestId('row'))[0]).toBeInTheDocument();
+  });
+
   it('shows an error when existing silence cannot be found', async () => {
     renderSilences('/alerting/silence/foo-bar/edit');
 
diff --git a/public/app/features/alerting/unified/api/alertmanagerApi.ts b/public/app/features/alerting/unified/api/alertmanagerApi.ts
index fa93bfd0e2d..c7ede90eea5 100644
--- a/public/app/features/alerting/unified/api/alertmanagerApi.ts
+++ b/public/app/features/alerting/unified/api/alertmanagerApi.ts
@@ -72,7 +72,9 @@ export const alertmanagerApi = alertingApi.injectEndpoints({
         // TODO Add support for active, silenced, inhibited, unprocessed filters
         const filterMatchers = filter?.matchers
           ?.filter((matcher) => matcher.name && matcher.value)
-          .map((matcher) => `${matcher.name}${matcherToOperator(matcher)}${wrapWithQuotes(matcher.value)}`);
+          .map(
+            (matcher) => `${wrapWithQuotes(matcher.name)}${matcherToOperator(matcher)}${wrapWithQuotes(matcher.value)}`
+          );
 
         const { silenced, inhibited, unprocessed, active } = filter || {};
 
diff --git a/public/app/features/alerting/unified/components/silences/SilencedInstancesPreview.tsx b/public/app/features/alerting/unified/components/silences/SilencedInstancesPreview.tsx
index 49235dd22e4..1e1b85da218 100644
--- a/public/app/features/alerting/unified/components/silences/SilencedInstancesPreview.tsx
+++ b/public/app/features/alerting/unified/components/silences/SilencedInstancesPreview.tsx
@@ -66,7 +66,7 @@ export const SilencedInstancesPreview = ({ amSourceName, matchers: inputMatchers
   if (isError) {
     return (
       <Alert title="Preview not available" severity="error">
-        Error occured when generating preview of affected alerts. Are your matchers valid?
+        Error occurred when generating preview of affected alerts. Are your matchers valid?
       </Alert>
     );
   }
diff --git a/public/app/features/alerting/unified/mocks/server/handlers/alertmanagers.ts b/public/app/features/alerting/unified/mocks/server/handlers/alertmanagers.ts
index 37f7f8e1c46..6677e2cace2 100644
--- a/public/app/features/alerting/unified/mocks/server/handlers/alertmanagers.ts
+++ b/public/app/features/alerting/unified/mocks/server/handlers/alertmanagers.ts
@@ -12,8 +12,37 @@ export const grafanaAlertingConfigurationStatusHandler = (
   response = defaultGrafanaAlertingConfigurationStatusResponse
 ) => http.get('/api/v1/ngalert', () => HttpResponse.json(response));
 
+const getInvalidMatcher = (matchers: string[]) => {
+  return matchers.find((matcher) => {
+    const split = matcher.split('=');
+    try {
+      // Try and parse as JSON, as this will fail if
+      // we've failed to wrap the label value in quotes
+      // (e.g. `foo space` can't be parsed, but `"foo space"` can)
+      JSON.parse(split[0]);
+      return false;
+    } catch (e) {
+      return true;
+    }
+  });
+};
+
 export const alertmanagerAlertsListHandler = () =>
-  http.get<{ datasourceUid: string }>('/api/alertmanager/:datasourceUid/api/v2/alerts', ({ params }) => {
+  http.get<{ datasourceUid: string }>('/api/alertmanager/:datasourceUid/api/v2/alerts', ({ params, request }) => {
+    const matchers = new URL(request.url).searchParams.getAll('filter');
+
+    const invalidMatcher = getInvalidMatcher(matchers);
+
+    if (invalidMatcher) {
+      return HttpResponse.json(
+        {
+          message: `bad matcher format: ${invalidMatcher}: unable to retrieve alerts`,
+          traceID: '',
+        },
+        { status: 400 }
+      );
+    }
+
     if (params.datasourceUid === MOCK_DATASOURCE_UID_BROKEN_ALERTMANAGER) {
       return HttpResponse.json({ traceId: '' }, { status: 502 });
     }