It takes a brave Labour leadership candidate to outflank the Liberal Democrats on Brexit after last month’s election result, but that is precisely what Jess Phillips did this morning.

Asked by Andrew Marr whether she could envisage campaigning to rejoin the EU should she succeed Jeremy Corbyn, the Birmingham Yardley MP said: “If our country is safer, if it is more economically viable to be in the EU, then I will fight for that, regardless of how difficult that argument is to make.”

Contrast that response with the one Daisy Cooper, the new Liberal Democrat MP for St Albans and a likely candidate for its vacant leadership, gave a few BBC studios away when asked the same question by John Pienaar: “Not right now.” Or, more pertinently, Keir Starmer’s: “We are going to leave the EU in the next few weeks; and it’s important for all of us, including myself, to realise that the argument for leave and remain goes with it. We are leaving. We will have left the EU.”

Whose is the right call? Both Cooper and Starmer speak for the vast majority of their parliamentary parties. Most MPs on the Labour and Liberal Democrat benches believe the argument is a lost cause in the medium term at the very least, and that to restart it would mean – in the words of one senior Lib Dem – “inviting oblivion”. Phillips, meanwhile, is making a virtue out of her honesty, no matter how politically toxic it may be – which, as her supporters in the PLP will tell you, is the entire point of her campaign.

It is a bold gambit, and while it might endear Phillips to some of the existing members she is seeking to win over – and the new ones she is actively trying to recruit – her interview has set alarm bells ringing in the PLP. Even MPs who agitated for Labour to adopt an unequivocally pro-Remain position and ended up dissatisfied with its manifesto stance concede that there is little appetite for rejoin among the grassroots. “That isn’t where the members are now,” says one. "I'm not sure she planned to say it. She struck me as unprepared on a number of issues, and responding off the cuff."

Though Phillips’ allies believe that candour is one of her assets, that the headline out of her first set-piece interview is such a controversial one – with little meaningful purchase in the PLP, trade unions or grassroots – underlines the risks of the approach.