UK 4 July 2016 Tom Watson plans "last throw of the dice" to achieve Jeremy Corbyn's departure Labour's deputy leader tells MPs that he will meet trade union leaders tomorrow to try and negotiate a settlement. Getty Images. Sign UpGet the New Statesman's Morning Call email. Sign-up Tom Watson is to meet trade union leaders tomorrow in a final attempt to negotiate the departure of Jeremy Corbyn. "A last throw of the dice" was how Labour's deputy leader described the move at the first Parliamentary Labour Party (PLP) meeting since MPs' vote of no confidence in Corbyn. Watson warned that "the window is closing" for an agreement, a sentiment shared by putative challengers Angela Eagle and Owen Smith whom he met today. The deputy leader held a 20-minute meeting with Corbyn this morning and urged him to resign having lost colleagues' backing. Three MPs who backed the leader in last week's confidence vote (Pat Glass, Liz McInnes and Andrew Smith) have since called for his departure. Fabian Hamilton, who abstained, has also demanded Corbyn's resignation. Members' support alone, Watson warned, was not enough. But a spokesman for the deputy leader said Corbyn "gave no indication that he would resign". Unless at least some of the "big four" unions - Unite, Unison, the GMB and the CWU - move against Corbyn, a leadership contest looks inevitable. The most dramatic moment of the evening was provided by Neil Kinnock, the man who defeated Labour's far-left in the 1980s. In a furiously impassioned speech, the former leader moved MPs to tears as he declared that he would not allow the party to split after 60 years as a member. "We are not leaving our party. We are going to fight and we are going to win!" he cried, thumping the table as he spoke. Kinnock emphasised that Labour chose to take "the parliamentary route to socialism" in 1918, not the revolutionary one. He also made a crack at the expense of Dennis Skinner, who noted that voters in supermarkets told MPs that Ed Miliband was unelectable. "Apply your supermarket test to Corbyn!" he quipped. Whether or not the Labour leader passes that test, his allies are confident he will pass the members' one. Update: This piece wrongly described Lyn Brown and Rob Marris (who abstained) as having supported Jeremy Corbyn in the no confidence vote. The error has been corrected. › Momentum, anti-Semitism and the problem with Labour's grassroots activists George Eaton is senior online editor of the New Statesman. Subscribe For daily analysis & more political coverage from Westminster and beyond subscribe for just £1 per month!