Jeremy Corbyn has walked out of an early evening meeting of party leaders with Theresa May after he realised the prime minister had invited the Independent Group spokesman, Chuka Umunna.

The Labour leader had been due to meet May to discuss the Brexit crisis alongside the SNP’s Ian Blackford, the Lib Dems’ Vince Cable plus the parliamentary leaders of Plaid Cymru and the Greens.

But those present said he quit the meeting once he realised that former Labour MP Umunna, who is not a party leader but the spokesman of the newly formed group of MPs made up of Tory and Labour defectors, had also been invited.

Umunna, however, claimed it was “extraordinary behaviour” and added: “I don’t think this is what people expect from a leader of the opposition at a time of crisis when the people that elect us to come together and see if there is a way forward.” Vince Cable said: “Jeremy Corbyn’s kinder, gentler politics was found wanting as he stomped out of the meeting before it began rather than breathe the same air as Chuka Umunna.”