Dominic Grieve, a leading Conservative rebel, said that he “will not facilitate” a Jeremy Corbyn government in an email seen by the New Statesman.

It is a further blow to Labour hopes that a caretaker or unity government can be established with Corbyn at its head.

In the email, Grieve, the former attorney general and key player in multiple government defeats, replied to a highly critical message about Corbyn’s letter asking for support to lead a caretaker administration saying that, “I entirely agree. I am not about to facilitate Jeremy Corbyn’s arrival in Downing Street.”