Clive Lewis has marked out his pitch for the Labour leadership by arguing Jeremy Corbyn’s failure to fight Brexit contributed to the party’s election disaster.

The shadow Treasury minister became the only candidate to argue the party should have adopted an out-and-out Remain position – because its “triangulating” damaged the Labour leader’s standing.

Mr Lewis – an early supporter of a Final Say referendum – described Brexit as “a hard-right political project” that Labour “had to fight with all its vigour”.

“If you pick a side, you have to then argue for that side, and argue for it comprehensively,” he told BBC Radio 4’s Today programme.

“One of the key USPs of Jeremy Corbyn was that he was an authentic politician. I genuinely believe that he was, but on the biggest political crisis of British modern politics we were unable, via Jeremy, to be able to take a position.

“I think actually we should have stood our ground and argued our case.”

The stance is in marked contrast to that of the other leadership candidates, including Rebecca Long Bailey, who finally broke her silence to confirm she plans to run.

The shadow business secretary criticised the party’s Brexit position, saying “our compromise solution satisfied too few”, but she did not set out what the party should have done instead.

Mr Lewis said that his personal experience on the doorstep had shown him that Mr Corbyn’s leadership was a problem for many voters.

The battle to replace Jeremy Corbyn as Labour leader Show all 8 1 /8 The battle to replace Jeremy Corbyn as Labour leader The battle to replace Jeremy Corbyn as Labour leader Keir Starmer The former director of public prosecutions undoubtedly has announced that he is standing for the leadership. He is highly-regarded by both left-wingers and centrists in the party. As Labour’s shadow Brexit secretary, he played a key role in the party’s eventual backing of a second referendum. Before becoming an MP, he was a human rights lawyer - conducting cases in international courts including the European Court of Human Rights. Launching his bid, Starmer said that Labour must listen to the public on how to change "restore trust in our party as a force for good." A YouGov poll places him comfortably in the lead as the preferred candidate of 36% of party members EPA The battle to replace Jeremy Corbyn as Labour leader Lisa Nandy Wigan MP Lisa Nandy has announced she wil stand for the leadership. In a letter to the Wigan Post she said she wanted to bring Labour "home" to voters in its traditional strongholds who have abandoned the party. Nandy went on to say that she understands "that we have one chance to win back the trust of people in Wigan, Workington and Wrexham." A YouGov poll shows that Nandy is the first preference for 6% of partymembers. Getty The battle to replace Jeremy Corbyn as Labour leader Rebecca Long Bailey A key ally of the current left-wing leadership of the party, the Salford & Eccles MP is viewed in some quarters as the natural successor to Mr Corbyn and describes herself as a “proud socialist”. Highly regarded by the shadow chancellor, John McDonnell. She won also won plaudits for her performance filling in for Corbyn both at prime minister’s questions and during the general election debates. The shadow business secretary grew up by Old Trafford football ground and began her working life serving at the counter of a pawn shop. Launching her leadership bid, Long Bailey said the party needs to make the positive case for immigration as a "positive force." She also broke with Corbyn over Trident, saying "If you have a deterrent you have to be prepared to use it." PA The battle to replace Jeremy Corbyn as Labour leader Angela Rayner - Deputy leadership Shadow education secretary Angela Rayner has joined the contest for deputy leadership of the party. After ruling herself out of running for the leadership, the Ashton-under-Lynne MP launched her bid for deputy warning that Labour faces the "biggest challenge" in its history and must "win or die." She is close with leadership contender Rebecca Long Bailey PA The battle to replace Jeremy Corbyn as Labour leader Rosena Allin-Khan - Deputy leadership Shadow sport minister Rosena Allin-Khan said Labour need to listen with "humility" to lost voters as she launched her bid for the deputy leadership. Writing in The Independent, the MP for Tooting refelcted: "We shouldn’t have ignored the warning signs in Scotland, and now we’ve paid the price in northern England, across the midlands and in Wales." PA The battle to replace Jeremy Corbyn as Labour leader Dawn Butler - Deputy leadership Shadow women and equalities secretary Dawn Butler was first to announce her bid for the deputy leadership. The Brent Central MP has served in Jeremy Corbyn's shadow cabinet since 2016 PA The battle to replace Jeremy Corbyn as Labour leader Ian Murray - Deputy leadership Labour's only MP in Scotland said that the architects of the party's "catastrophic failure" in the December election can not be allowed to lead the party forward PA The battle to replace Jeremy Corbyn as Labour leader Richard Burgon - Deputy leadership Shadow justice secretary Richard Burgon is standing as a continuity candidate, flaunting his loyalty to Jeremy Corbyn and saying it is wrong to blame the current leader for the election defeat PA

But he also pointed to problems in the party’s heartlands going back decades, saying: “For the last 40 years in this country there has been a decline in those votes in those areas where we collapsed in the general election.

“And this is something that has been going on for 40 years, and that includes over the period of 1997 to 2010. So to understand what actually went wrong with this vote, you need to look back further than just 2015, or 2010.

“It is like trying to work out the causes of the Second World War by going back no further than 1938. You have to go back to 1914, and possibly beyond.

“We have to work out why were we not able to connect to people in these heartlands, in the north, in the east midlands. Why couldn’t we get our message across to them?”

Labour’s ruling national executive committee will meet next Monday to decide the format of the election, with the intention of installing the new leader by the end of March.

In her newspaper article, Ms Long Bailey pledged to champion “progressive patriotism”, while avoiding criticism of Mr Corbyn or of his handling of the antisemitism issue.