Jeremy Corbyn's leadership turmoil continued on Monday evening (18 July 2016) after only 46 other Labour MPs supported him in voting against the renewal of the UK's nuclear deterrent, Trident. The House of Commons vote saw 472 to 117 MPs back Thersea May's government over the £41bn ($54bn) upgrade to the continuous at-sea programme.

But the pressure on Tuesday comes from Corbyn's two leadership rivals, Owen Smith and Angela Eagle. Anti-Corbyn activists are worried that the shadow cabinet ministers could split the so called Labour 'soft left' vote and enable a repeat of the 2015 Labour leadership contest, which saw Corbyn romp to victory with almost 60% of the vote.

An opinion poll from YouGov, of more than 1,000 Labour members between 15 and 18 July, as featured in The Times newspaper on Tuesday, makes grim reading for the challengers.

Only 15% of the respondents said they would back Smith, while just 21% would throw their support behind Eagle. Corbyn, on the other hand, is predicted to attract 54% of the vote.

Eagle and Smith addressed the weekly meeting of Labour's parliamentary party (PLP) on Monday afternoon, and the leadership hopefuls would have to attract 51 nominations from Labour MPs and MEPs before the Wednesday deadline to get on the ballot. Corbyn, in contrast, will be automatically on the ballot after a ruling from Labour's National Executive Committee.

The former shadow foreign secretary Hilary Benn, an Eagle supporter, took to the airwaves on Tuesday morning to insist that Labour would not split over the leadership crisis.

The senior Labour MP also told BBC Radio 4's Today programme that there is a "strong view" in Labour's PLP that there should only be one Corbyn challenger. "Jeremy has made a huge contribution and will continue to do so," he added. A decision is reportedly expected at around 5pm BST on Tuesday on whether Eagle or Smith would go forward as the 'unity' candidate.