Owen Smith, the Welsh Labour MP who unsuccessfully challenged Jeremy Corbyn in 2016, has been branded "delusional" after making a bold assertion about the 2017 general election on Sunday 2 July.
Smith told Sky News' Sophie Ridge that he may have won the vote for Labour if only the party's members had picked him over his left-wing rival last year.
"Many people will remember you as the man who challenged Jeremy Corbyn last year. You said that his leadership at the time was a 'cataclysmic failure, leaving Labour teetering on the brink of obscurity'," Ridge said.
"Well, it doesn't quite seem that way after the election [when Labour won 30 extra seats] does it? Why did you get him so wrong?"
Smith, who returned to Corbyn's top team after the election as shadow secretary of state for Northern Ireland, argued that his stance was in line with the political consensus at the time.
"My view, Sophie, was that Labour wasn't going to get close to winning with Jeremy as our leader," he said.
"I was clearly wrong about that because we did very well at the election, gained 30 seats and almost [secured] 13 million votes. I wasn't anticipating that and Jeremy, in that regard, absolutely proved me wrong and many people wrong."
Smith added: "We are now within a chance of winning an election, the Tories are clearly riven right now. They could collapse now at any moment and Labour needs to stand ready to form a government."
Ridge continued: "If you had won that leadership election, do you think you would have done as well as Jeremy Corbyn did?" Smith replied: "I don't know, I hope so, I hope I might have even got us to win."
The comments, which Labour MP John Mann said showed an "extraordinary level of delusion", come just days after Corbyn sacked three of his frontbench team (Catherine West, Ruth Cadbury and Andy Slaughter) for voting in favour of keeping the UK's in the EU's single-market and customs union.
Such a move would mean that Britain would not be allowed to broker its own free trade arrangements with non-EU nations and would likely result in no substantial changes to free movement of people rules, which the Labour election manifesto said must change after Brexit.
With Theresa May wounded by the election result and the government facing increased scrutiny over the Grenfell Tower fire disaster, Corbyn had enjoyed a post-election opinion poll lead over the Conservatives. But the latest Survation survey, of more than 1,000 people between 28 and 30 June, put the Tories on 41% (+1) and Labour on 40% (-4).