THE firm line taken by Jeremy Corbyn and Emily Thornberry at the weekend rally in Broxtowe gives a lead to our movement on how to respond to breakaway MPs.

“Not understanding where we have come from is a bad mistake,” the Labour leader charges. He is correct: the Labour Party is a unique phenomenon in British politics.

The original two-party system that evolved from the 17th to 19th centuries in Britain was top-down. The Whigs and the Tories, later to evolve into the Liberals and the Conservatives, were alliances of MPs formed within Parliament – just as the so-called Independent Group is.

Labour is different. It was formed by trade unions as the political expression of the interests of a democratic mass movement.

MPs wield disproportionate influence over the direction of the party, but it does not belong to them. Labour is the biggest political party in Europe, with well over half a million members.

And it is a party built to further the interests of organised labour, which is why the role of affiliated trade unions continues to be crucial.

Large numbers of MPs have never accepted Corbyn’s leadership. Tied to an agenda of privatisation, welfare cuts and war, the election of a leader committed to public ownership, the redistribution of wealth and peace was anathema.

Fortunately it was not up to them. Corbyn was elected by the members. MPs tried to force him out in 2016. Rightwingers in the party hierarchy even tried to remove his right to be on the ballot in the subsequent leadership election, so flimsy was their commitment to democratic principle compared with their commitment to capitalism.

That failed, so right-wing MPs, imprisoned like much of the media in a Westminster bubble that has failed to reflect changing political realities, assumed they would wait till a general election and voters would confirm their own view by rejecting Corbyn.

But 2017 saw the biggest increase in Labour’s vote since 1945.

The campaign revealed the extent of suffering caused not just by Tory austerity, but by four decades of neoliberalism – broken communities, rampant insecure work, soaring public and private debt, unaffordable housing, a return to a past we thought was gone forever as in 21st-century Britain people starved to death for lack of money.

Many MPs then recognised what Labour members and voters were telling them: that the status quo has failed and it is time for something radically different.

But for others, committed to the maintenance of the capitalist system whatever the human or environmental cost, it does not matter whether Corbyn’s ideas are popular. He must be defeated.

This is the motivation behind most of the attacks on him, and this is the reason why a handful of MPs have decided to walk away from the movement that gave them their careers.

Compromise with Corbyn’s enemies is not an option, because their aim is simply his removal.

Our response must be a democratic one. Corbyn and Thornberry attracted a public crowd the so-called Independent Group could not dream of yesterday.

The labour movement must mobilise across the country for an election that will sweep away the Tory government together with these “independents” who say they will support it in any confidence vote.

And we must fight for MPs who better reflect the interests of working people. Paddy Lillis’s remarks in tomorrow's Morning Star on the Usdaw union’s work to bring more trade unionists into politics are encouraging, as is the groundwork his union and others are putting in, now, for a campaign to win a general election for Labour.

If our movement fights for the changes we need in workplaces and communities across Britain, this trickle of deserters will be no more than a footnote in the history of Britain’s transformation into a democratic and socialist society.