Speaking at the British Ambassador’s residence on Tuesday night, Mr Healey said the public had “given us a mandate to serve them and serve our country”.

“We’re getting on with the job in government,” he said.

“You will see this week that Keir Starmer leads our determination.

“Our determination that Britain will step up our support for Ukraine, that we’ll fulfil our Nato commitments, secure our role as Europe’s leading nation in Nato and make Britain democracy’s most reliable ally around the world.”

He said that Labour was the “party of Nato”, pointing to the work on the original Nato treaty conducted by a Labour foreign secretary, Ernest Bevin.