In 1903 he transferred to Somerset County Council's newly formed local education authority, where he worked in the School Management Department as a committee clerk.

In July 1921 he campaigned directly to MPs to oppose a clause in the government's Finance Bill which would impose Corporation Tax on Co-ops.

When Labour formed its first government in January 1924, Ramsay MacDonald made Alexander Parliamentary Under-Secretary of State to the Board of Trade, under Sidney Webb and Emmanuel Shinwell.

The Co-op's Parliamentary Committee had an acting secretary in Alexander's place whilst he was in government, but he continued to take part in appeals to ministers.

Although many had expected Alexander to be appointed President of the Board of Trade, this position went to William Graham, protégé of the Chancellor of the Exchequer, Philip Snowden.

MacDonald's primary concern was international disarmament, and Alexander persuaded the Admiralty to reduce their demands for new cruisers as a prelude to negotiations aimed at ending naval rivalry with the U.S..

Alexander was prominent on the Opposition front bench, leading attacks on the government's policies, but was careful not to exploit the widespread dissatisfaction with pay cuts in the armed forces (especially the Invergordon Mutiny), concerned that the military should not become involved in political matters.

He led opposition to renewed government plans to impose Corporation Tax on co-op stores, a fight that was lost this time with the 1933 Finance Bill.

He was active in the Brotherhood movement (an organisation for nonconformists), spoke at rallies for the League of Nations, wrote columns for Reynold's News and gave lectures on the BBC.

Attlee, now leader of the PLP, asked him to join a new defence committee, working with Shinwell and Jack Lawson to reverse the pacifist ideals which had prevailed under Lansbury.

In 1937, with Hugh Dalton and Hastings Bertram Lees-Smith, he persuaded the PLP to put aside its mistrust of the Baldwin government and support the Service Estimates Bill which began rearmament.

Following the outbreak of World War II, Alexander, like all leading Labour figures, opposed forming a coalition government under Neville Chamberlain.

He worked with Arthur Greenwood, and against Herbert Morrison, who favoured Lord Halifax as successor, to convince Attlee and the party's Executive to support Churchill.

In the closing days of April 1940, Churchill met with Alexander, Clement Attlee and Sir Archibald Sinclair to discuss the possibilities for a coalition government.

[5] An example was Churchill's decision to send Force Z including the battleship Prince of Wales and the battlecruiser Repulse to Singapore without, as it transpired, adequate air support.

Campaigning in the election in July, he drew a sharp distinction between Churchill and the Conservative Party, suggesting that the Tories would sideline the wartime leader as they had done Lloyd George in 1922.

A member of the Cabinet following Labour's victory, Alexander strongly supported the Foreign Secretary, Ernest Bevin, sharing his goals of maintaining Britain's influence and opposing the Soviet Union.

In 1946 he deputised for Bevin at the Paris Peace Conference, and was part of the Cabinet delegation to India, under Stafford Cripps, exploring possibilities for independence.

[10] He was responsible for formulating the system of national service and faced a protracted fight against Labour backbenchers who opposed the continuation of conscription in peacetime.

In January 1947 he was one of six ministers on the Gen 75 Committee that secretly authorised Britain's nuclear programme; in March he was in the negotiations for the Treaty of Dunkirk, laying the foundations for NATO.

[12] Although he never made it into the "top five" of the Labour government (Attlee, Bevin, Morrison, Dalton and Greenwood, later replaced by Cripps), he remained an influential member throughout.

In December 1955, following the resignation of Lord Jowitt, Alexander was asked by Hugh Gaitskell to take over as leader of the small group of Labour peers.

He also supported Tony Benn's campaign to renounce his peerage, and opposed Britain's early attempts to join the European Economic Community.

His last appearance in the Lords was shortly before Christmas that year, when he fiercely defended Harold Wilson's foreign policy from Tory accusations of disloyalty.