SENIOR Labour politicians in south Essex have added to pressure on party leader Jeremy Corbyn to step down.

Mr Corbyn yesterday insisted he would “not allow a coup” despite 21 out of 31 members of his shadow cabinet leaving their posts in protest against his leadership.

The Labour leader has been heavily criticised for his lack of commitment to the Remain campaign ahead of last week’s EU referendum, with one party colleague labelling Mr Corbyn’s efforts as “lacklustre”.

Baroness Smith of Basildon, who is Labour’s leader in the House of Lords, is one shadow cabinet member who will remain in her post.

But it is believed that both Lady Smith and Lord Bassam, Labour chief whip in the Lords, will boycott shadow cabinet meetings while Mr Corbyn remains as leader.

The duo were both elected to their positions by party peers in the Lords, and were therefore not directly appointed by Mr Corbyn.

It comes as a group of more than 50 Labour parliamentary candidates signed a letter urging Mr Corbyn to step down.

Gavin Callaghan, who stood for election in Basildon and Billericay, was one of 57 candidates from the 2015 General Election to sign the letter, sent to Parliamentary Labour Party chairman John Cryer.

Borough councillor Mr Callaghan is the current leader of the Basildon branch of the party.

The letter states that Labour needs a leader who would be seen as a “credible Prime Minister” with a vision for the whole of Britain.

Part of the letter reads: “We admire the service that Jeremy Corbyn has offered to our party as leader in the past year and his long service as an MP and within the union movement.

“However, we believe we must accept we cannot achieve our shared ambitions for the future of the UK without a leader able to command the confidence of the country.”

The Labour Party crisis began on Saturday when shadow foreign secretary Hilary Benn was sacked after telling Mr Corbyn he no longer had confidence in him.

It led to a further 21 shadow cabinet members resigning in protest, as well as the boycott of the party’s two most senior peers.

Deputy party leader Tom Watson told Mr Corbyn he had “no authority” among MPs.

Essex Labour activist Julian Ware-Lane, who stood in Southend West at last year’s General Election, was not one of the 57 signatories of the letter to Mr Cryer.

He said: “I won’t be asking for his resignation. I don’t think now is the appropriate time to replace him, but it looks like events are overtaking my particular wishes.

“If there are questions about Jeremy’s leadership , just let the dust settle on the referendum first and make these decisions when we are not in shock.”

Southend Labour leader Ian Gilbert labelled Mr Benn’s sacking a “mistake”, but insists referendum defeat was not entirely Mr Corbyn’s fault.