Shadow Brexit secretary Sir Keir Starmer said there were “unresolved” issues in the parliamentary party after Mr Corbyn’s reshuffle, a shake-up which saw Labour plunged back into in-fighting.
Leading MPs at odds with Mr Corbyn are reported to be setting up their own informal body to put forward policy initiatives in competition with the official shadow cabinet, The Press Association reported.
Asked about the “shadow shadow cabinet” on the BBC’s Andrew Marr Show, Sir Keir said: “There are unresolved issues in the parliamentary Labour Party. We do need to resolve them as soon as possible. We need to be an outward-looking, confident party, rather than an inward, divided party, so we need to address that.
“I respect colleagues who want to make their voice heard from different places, whether it’s the backbench, the mid bench, through select committees, or on the front bench.”
Sir Keir, one of only a handful of the 63 people who quit the shadow team in protest at Mr Corbyn in June to return to the front bench, side-stepped directly answering when asked if the Labour leader would make a good prime minister.
The comments came as Mr Corbyn’s controversial choice for shadow attorney general, Shami Chakrabarti, compared the Labour Party to a “war zone”.
Lady Chakrabarti said she had received racist hate mail since becoming a Labour peer after producing a report on anti-Semitism in the party which some Jewish groups branded a whitewash.
“I think that I drew criticism the moment I joined the Labour Party. I joined a party in civil war at a time when the country was in crisis.
“And even if you think you are driving an ambulance into a war zone, you are going to take some flak, and that’s what happened.
“I didn’t expect, perhaps, some of the racist hate mail, often laced with misogyny, but I’m not here to whinge,” she told Channel Four News.
Mr Corbyn’s reshuffle provoked fresh turmoil in Labour ranks as the chairman of the parliamentary party, John Cryer, wrote a fiery letter to MPs revealing that he and sacked chief whip Rosie Winterton had been kept in the dark on the shake-up despite holding talks with the leadership on electing some of the posts to the body.
Bermondsey MP Neil Coyle told Channel Four News: “We had the facade of discussions and negotiations going on about shadow PLP elections which were a complete farce when the leader’s team had already planned what they would do instead.”
Key Corbyn ally, and shadow foreign secretary, Emily Thornberry, insisted it was unfair to criticise the leader for being “too strong”, and that the issue of elections to the shadow cabinet was still on the table.
Meanwhile, it was revealed that the pro-Corbyn Momentum organisation now has more than 20,000 members.
Some anti-Corbyn MPs have accused it of being a party within a party, but leading member Adam Klug told the Labour List blog that it only posed a threat to the Tories.