Fresh Labour Party divisions have opened up over Brexit with a call from deputy leader Tom Watson for a second referendum before any general election.

In a speech on Wednesday, Mr Watson said a single-issue Brexit election may not break the deadlock in Parliament – something only a second referendum can achieve with certainty.

He also argued that, if a referendum were to follow an election, then Labour should commit “unambiguously and unequivocally” to campaign for Remain.

His latest intervention puts him on a fresh collision course with Labour leader Jeremy Corbyn, who has made clear his priority is for an election once Parliament has closed off a no-deal Brexit.

Addressing the TUC in Brighton on Tuesday, Mr Corbyn confirmed an incoming Labour government would hold a new referendum – with Remain and a “credible” option for Leave on the ballot paper – but he has yet to say which he would support.

The latest row follows a series of clashes between the two men over Mr Corbyn’s reluctance to embrace a second referendum and the party’s handling of complaints of anti-Semitism.

Shadow Brexit secretary Sir Keir Starmer sought to play down the divisions, insisting the party was united around a second referendum, but acknowledged that discussions were ongoing.

“At the moment there is a good discussion going on but we are very united having that discussion; we don’t want to shut down discussion in our party,” he said.

In his speech to the Creative Industries Federation, Mr Watson said that, while a Brexit election might at the moment seem “inevitable”, such single issue campaigns were never desirable.

“Boris Johnson has already conceded that the Brexit crisis can only be solved by the British people,” he said.

“But the only way to break the Brexit deadlock once and for all is a public vote in a referendum. A general election could fail to solve Brexit chaos.”

He argued that it was not too late for Labour to win back Remain voters put off by confusion over the party’s position on Brexit, if they were to commit clearly to campaign to stay in the EU.

“My experience on the doorstep tells me most of those who’ve deserted us over our Brexit policy did so with deep regret and would greatly prefer to come back; they just want us to take an unequivocal position that, whatever happens, we’ll fight to remain, and to sound like we mean it,” he said.

“If we did it, we could win, whereas if we don’t, I fear we won’t.”

Conservative Party chairman James Cleverly said Mr Watson’s comments showed Labour was determined to cancel the 2016 referendum result.

“This latest trick would mean delaying Brexit again for up to a year, handing over £250 million a week to Brussels for no purpose. Labour are running scared of an election and only offer more dither and pointless delay,” he said.

“Only Boris Johnson and the Conservatives will deliver Brexit by October 31, no ifs or buts, so we can move on and focus on the issues that matter to people – investing in the NHS, reducing violent crime and cutting the cost of living.”

Meanwhile, Sir Keir used a speech to the TUC in Brighton to insist that Labour would not be silenced in its bid to prevent a no-deal Brexit by the Prime Minister’s decision to suspend Parliament for five weeks.

“Johnson now thinks that, by shutting down Parliament, he will shut us up. Nothing could be further from the truth,” he said.

“Just as we worked throughout the summer to pass a law preventing no-deal, so we will work each and every day we are shut down to enforce that law.”