Former director of political operations John McTernan believes the Labour Party will only continue as a "vanity project" if Jeremy Corbyn stays in power.
Owen Smith has announced his intention to stand against Corbyn, whilst Angela Eagle has already launched her bid against the current leader.
"We just need anybody but Corbyn, that's the requirement at the moment, and unfortunately there are two people splitting the vote," he told Sam Delaney.
"Jeremy Corbyn has said the real reason Labour didn't win in 2015 is we weren't left wing enough, so we should go more left wing," he added. "As long as that's what his supporters want, and that's what he wants, Labour will move further and further away from power."
"The prospect is a shattering defeat in 2020, or whenever Theresa May chooses to hold an election.
"[It won't continue] as a national party that can win elections, it's certainly able to continue as a vanity project which is the intention of Corbyn and McDonnell."