At the end of December 1944 he was adopted as Labour candidate for Grimsby which was then held by Walter Womersley for the Conservatives with a small majority.

This appointment did not stop Younger from trying to understand the lives of his constituents better: on 28 August 1945 he set sail on the steam trawler Marano from Grimsby as a 'spare hand' for an eight- or nine-day voyage to North Sea fishing grounds.

His abilities had caught the eye of Clement Attlee, and in a government reshuffle on 7 October 1947 he became Parliamentary Secretary to the Home Office.

At the time of the outbreak of the Korean War in June 1950, Bevin was ill and Younger played a central role in determining Britain's diplomatic reaction.

Younger tried to assure the Chinese government that United Nations forces would not pursue the North Korean army further and attempt to invade China.

Younger was rated a success by Attlee but was not of sufficient stature to take over when Bevin finally moved from the Foreign Office due to ill health in March 1951.