The beginning of the 1980s saw the rise of the left wing inside the Labour Party behind the figure of Tony Benn.
The 1974-9 Labour government had pushed through 'monetarist' free market policies that reduced the living standards of workers, doubled unemployment and stoked up racism.
This provoked rebellion in the party and the unions. In an unprecedented 45 votes on different issues in the House of Commons, 50 or more Labour MPs rebelled against the government.
Trade unionists struck against the government's pay limits in 1978-9 in what came to be known as the Winter of Discontent.
Many people pledged that they would not allow such a right wing Labour government again.
The Tories won the general election in 1979. The following year Michael Foot, a figure from the party's left, was elected Labour leader.
A special conference at Wembley in 1981 voted through changes to Labour's constitution that made it more democratic.
The pinnacle of the left's campaign was Benn's challenge to right winger Denis Healey for deputy leader in 1981. Benn ran Healey close, losing by less than 1 percent.
A number of major figures on the right of the party split to form the SDP, hitting Labour's support.
While the left felt that it was riding to triumph in the party, the split put pressure on the Labour leadership to move rightwards to compete for the 'middle ground'.
The union leaders who had been willing to back the left to punish Labour's right for the 1974-9 government started to get nervous.
In 1982 a gathering of senior trade union leaders and Labour Party figures agreed 'the Peace of Bishop's Stortford'. It attacked the left as 'divisive'.
Tony Benn agreed not to stand again for deputy leader and the left began to fall back. Foot led Labour MPs in backing the slaughter of the 1982 Falklands War.
Labour leaders began a witch-hunt against the supporters of the left wing Militant newspaper in the party. Many others on the left in the party stood by or backed the purges.
Margaret Thatcher's Tories won a landslide victory in the 1983 general election. This saw a further move right as Neil Kinnock and Roy Hattersley became leader and deputy leader of the Labour Party.
Kinnock had been a left wing rebel MP during the 1970s. But now he and Hattersley began to shift the party to the right.
The left retreated into 'municipal socialism' – focusing on winning power in local government.
A number of Labour-controlled councils, including the Greater London Council (GLC), Liverpool and Sheffield, pledged to resist the Tories' cuts even if it meant breaking the law.
Kinnock replied that they should stay in office and act within the law even if this meant cutting services. Labour councils across the country eventually gave up the fight.
This coincided with the end of the 1984-5 Miners' Strike. The defeat of these struggles confirmed to Kinnock that Thatcherism was triumphant and that Labour had to attempt to appeal to the new 'affluent' workers.
The witch-hunt against Militant was stepped up. In the run-up to the 1987 election, Kinnock ditched Labour's commitment to the renationalisation of all the public services that the Tories had privatised.
All vaguely left wing policies were thrown out. Kinnock had begun the long march rightwards that later led to New Labour.
Labour has been wracked by numerous crises during its existence. Each crisis has seen a battle between the left and the right in the party, with the right eventually emerging victorious.
The left's commitment to the party and parliament means that it has repeatedly backed down at crucial moments to preserve the 'stability' and 'unity' it believed was required for Labour's success.
This is because the Labour project, even for the left, is about reformism – a selected few changing society on the behalf of the majority.
Reformism continues to have a hold in a world where working people feel they have no power. This means that the Labour Party is not finished. It has recovered from each crisis and gone on to win elections.
But its declining membership, fractured loyalties, and the alienation of millions from official politics means that its problems will continue.
Many in Labour are unhappy about its direction. Socialists outside Labour will continue to find many opportunities to work alongside those in the Labour Party and to debate the way forward for the left.