Boris Johnson is considering not replacing Lord Geidt as the ethics adviser who rules on whether ministers, including the Prime Minister, break the rules.

Downing Street said on Thursday he would instead conduct a review into the “vitally important” function after the peer resigned over a plan risking a deliberate breach of the ministerial code.

Lord Geidt clung onto the role despite suggesting Mr Johnson may have broken the rules by being fined over partygate and having considered the controversial funding of the Downing Street flat refurb during an “especially busy year”.

But he ultimately quit as ministerial interests adviser over a plan, thought to involve Chinese steel tariffs, that may breach British obligations to the World Trade Organisation.

“This request has placed me in an impossible and odious position,” the peer wrote to the Prime Minister.

Labour demanded a direct replacement for Lord Geidt after he became the second man to resign from the role during Mr Johnson’s premiership, and a union representing civil servants warned that the code is the only way workers can raises complaints of misconduct, bullying or sexual harassment against ministers.

But the Prime Minister’s official spokesman said he would take time to “carefully consider” how best to fulfil the role of ensuring “rigorous oversight and scrutiny of ministerial interests” as he raised the possibility of it being axed.

“We haven’t made a final decision on how best to carry out that function, whether it relates to a specific individual or not,” the official said.

“He (Mr Johnson) will carefully consider that before setting out the next steps.

“It could continue as it was before, but he hasn’t made a final decision on it.”

The review will delay finding a replacement, with the post having been empty for five months before Lord Geidt succeeded Sir Alex Allan.

Sir Alex resigned in 2020 after the Prime Minister refused to accept his finding that Home Secretary Priti Patel had bullied civil servants.

Mr Johnson’s spokesman suggested there was no plan to wait for a new adviser before going ahead with the controversial plan that provoked Lord Geidt’s resignation.

The official suggested the proprietary and ethics team in the Cabinet Office might oversee the ministerial code in the meantime, but this Government team would lack any semblance of independence that the adviser had.

Deputy Labour leader Angela Rayner said: “There are now no ethics left in this Downing Street regime propped up in office by a Conservative Party mired in sleaze and totally unable to tackle the cost-of-living crisis facing the British people.

“The Government must not only appoint a new watchdog but back Labour’s plan to restore standards. This Prime Minister has debased standards and rigged the rules for far too long. It is time for the Conservatives to do the right thing and remove him from office.”

Dave Penman, the general secretary of the FDA union that represents civil servants, said: “The ministerial code is the only mechanism a civil servant can use to raise a complaint of misconduct, bullying or sexual harassment against a minister.

“Confidence in that process has already been severely damaged by the Prime Minister’s refusal to accept that the Home Secretary had breached the code, despite being found to have bullied staff.

“If the Prime Minister does not intend to replace Lord Geidt, then he must immediately put in place measures that ensure a civil servant can, with confidence, raise a complaint about ministerial misconduct.”