Due to his experience as a professional joiner, he made a speciality of the construction industry and its employment practices, but was also concerned with trade union issues in general.

However, when the Soviet Union was invaded by Nazi forces in 1941, Heffer resigned from Labour and joined the Communist Party of Great Britain; he said that "To me, Stalin was the greatest of men".

Also in 1965 Heffer protested outside the United States embassy against the use of napalm and gas in the Vietnam War, and in Parliament against the diplomatic support given by the government.

By 1970 he was rated as one of the most effective of the large 1964 intake of Labour MPs: in David Butler's The British General Election of 1970 (page 4), he was identified as a leading figure in the Tribune Group, which had been established in 1964.

Heffer regarded unemployment as the worst catastrophe in running the economy and often demanded nationalisation of firms which threatened mass redundancies.

In August 1967, Wilson, who recognised his abilities, asked Heffer to take a junior post at the Ministry of Technology under Tony Benn.

Heffer refused, citing his opposition to government economic policy, and demanded the resignation of James Callaghan as Chancellor of the Exchequer.

He also began a campaign to win a place on the National Executive Committee at this conference, standing again each year and steadily building his support.

In February 1968 Heffer was one of the Labour MPs to rebel against the government's decision to withdraw British passports from the Kenyan Asians who were arriving at Heathrow Airport in increasing numbers, fleeing persecution in Kenya.

He maintained pressure on the government over the Vietnam war and criticised the Greek military dictatorship of 'the Colonels' for "bestial and barbarous practices".

On two of the issues which divided the Labour Party at the time, Heffer took the side of the rebels: he rejected the proposals for reform of the House of Lords as too weak, preferring fundamental reform or preferably abolition, and he worked to change proposals in Barbara Castle's trade union white paper In Place of Strife (a cabinet rebellion later forced the government to abandon it completely).

Prentice's refusal to pledge support to five dockers imprisoned under the Industrial Relations Act appalled Heffer who considered resignation.

Heffer had revised his opinions on the EEC in 1970, deciding that the spending on the Common Agriculture Policy was excessive and too big a burden on the budget.

Heffer worked together with Benn to try to establish the National Enterprise Board, which would provide industry with investment funding and have the ability to take failing firms into public ownership.

In the meantime, the government prepared for the referendum on the European Communities through which Wilson hoped to settle the differences over the issue in the country and the party.

At the 1975 Labour conference his bid for a National Executive Committee (NEC) seat was finally successful as he defeated Denis Healey.

However he did support Benn's 'Alternative Economic Strategy' which called for government assistance to industry, import restrictions, surcharges on high net income and capital and controls on banks.

In intra-party matters, Heffer opposed taking action against the Militant tendency after a report by the party's national agent Reg Underhill raised concerns over its activities.

He was one of the left-wing members of an ad hoc sub-committee of the NEC which undertook the task of cutting an overlong manifesto for the 1979 general election down to a manageable size.

The left wanted to have the Leader elected by an 'electoral college' which would include affiliated trade unions and individual Constituency Labour Parties.

In June 1982 the NEC discussed Militant again, with Heffer proposing that all members of the Labour Party subscribe to a 'statement of democratic socialist principles' which was defeated by 22 votes to 5.

At the 1982 Labour Party conference the right-wing won back control of the NEC, and at its first meeting the left-wing were voted out of all their chairmanships in a coup organised by John Golding.

When the council met on 29 March 1984 it was told clearly that the Militant proposed 'deficit budget' contained an illegal £30 million deficit, but no alternative could get a majority and it went through.

In a desperate attempt to avoid bankruptcy, on 27 September the council issued 90-day redundancy notices to its entire workforce, using a fleet of taxis to deliver them.

One sixth of the book is devoted to expressing his views that Kinnock's "betrayal of socialism" led to "a rigid party discipline and the expulsion of Militant supporters".

Heffer's constituency had become increasingly safe for him over the years and at the 1987 election he had the largest absolute Labour vote in the country and a rock-solid 23,000 majority.

Tony Benn was chosen to challenge Kinnock as Leader, while Heffer and John Prescott (from the Tribune group) opposed Roy Hattersley for the Deputy Leadership.

When Parliament was recalled to debate the invasion of Kuwait in September 1990, Heffer made what he knew would be his last speech in the House of Commons to urge the United Kingdom not to go to war.

In January 1991 he attended the House of Commons to vote against the Gulf War in a wheelchair, when John Major crossed the floor to shake his hand.

He was especially targeted in the satirical strip Battle for Britain which ran in the magazine Private Eye between 1983 and 1987 — Margaret Thatcher's second term in office as Prime Minister.