Boris Johnson is considering scrapping the role of ethics adviser after the resignation of Lord Geidt, who accused him of making a mockery of his position overseeing standards in government. The prime minister’s official spokesperson said Johnson would not immediately start looking for a replacement for Geidt, but would instead review the system of enforcing the ministerial code. The spokesperson said it was “vitally important” that the code was upheld, but that the prime minister had not yet decided the “exact mechanism” of doing so. Labour’s deputy leader, Angela Rayner, said the move demonstrated “there are no ethics in Boris Johnson’s Downing Street”. She said: “It appears he will now try to keep it that way, content to further debase standards in public life and demean his office.” The Liberal Democrat leader, Ed Davey, said: “Boris Johnson has no ethics, so it’s no surprise he wants to scrap his ethics adviser.” In a strongly worded resignation letter published by Downing Street on Thursday, Geidt cited Johnson’s problematic response to the Partygate scandal as one reason for his departure. But he made clear the final straw had been a request from Johnson for Geidt to approve a plan to extend tariffs on steel imports, which could break World Trade Organization (WTO) rules, putting the government in breach of international law. The ministerial code includes an “overarching duty,” for ministers to comply with the law. Geidt said the request had put him in an “impossible and odious position”. “The idea that a prime minister might to any degree be in the business of deliberately breaching his own code is an affront. A deliberate breach, or even an intention to do so, would be to suspend the provisions of the code to suit a political end. “This would make a mockery not only of respect for the code but licence the suspension of its provisions in governing the conduct of Her Majesty’s ministers. I can have no part in this.” In his reply to Geidt, Johnson insisted his intention was to seek Geidt’s “advice on the national interest in protecting a crucial industry, which is protected in other European countries and would suffer material harm if we do not continue to apply such tariffs”. Geidt’s predecessor, Alex Allan, quit in November 2020 after the prime minister ignored his finding that Priti Patel had bullied civil servants. Allan said he was “very sad” that his successor had also felt forced to quit. “I just felt really upset that Christopher Geidt, who is a very honourable man, had been put in a position where he felt he had no option but to resign. “I’ve known him for many years, and he’s a dedicated public servant, a man with lots of integrity, and he wouldn’t have taken this decision lightly. It’s very sad that it’s come to this,” he told the BBC. Asked whether he believed Johnson was a man of integrity, Allan replied: “I’m not going to answer that.” William Wragg, the Conservative chair of the Public Administration and Constitutional Affairs Committee , which grilled Geidt on Tuesday, said: “For the prime minister to lose one adviser on ministers’ interests may be regarded as misfortune, but to lose two looks like carelessness.” Geidt suggested during the cross-party hearing that it was “reasonable” to suggest Johnson may have broken the ministerial code, when he received a fixed penalty notice for attending a birthday party during a 2020 lockdown. The chancellor, Rishi Sunak, told ITV News on Thursday that he did not believe he had broken the ministerial code, despite receiving a fixed penalty notice for the same party – because Johnson is the final judge of it. “Lord Geidt I think acknowledges the ultimate arbiter of our ministerial code is the PM, that is how our system works, and the prime minister has fully addressed that matter,” he said. Johnson recently published a letter, at the urging of Geidt, explaining why he did not think he had broken the code. His reasoning included the fact that he had not believed he was breaking Covid rules at the time. Sunak said he was “sad to see what Lord Geidt has written, and sorry to see him go”. Dave Penman, general secretary of the FDA union representing senior civil servants, urged the government to put in place measures immediately to ensure concerns about ministers’ behaviour can still be investigated. “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,” he said. “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.” Rebel Tory MPs hoping to drum up support for a future vote of no confidence in Johnson said Geidt’s abrupt departure would not necessarily help their cause. One former minister said Geidt’s rationale was “slightly obscure” despite the strong language in his letter. Many at Westminster, including some government officials, were mystified as to why Geidt had been asked to rule on the steel tariffs, which were extended for 12 months a year ago using emergency legislation. Catherine Haddon, of the Institute for Government, said: “What is somewhat baffling is what he was being asked to adjudicate on and why, because the government have had a series of cases, including Northern Ireland but also others, on international law and their willingness to breach it.” Peter Holmes, of the UK Trade Policy Observatory at Sussex University, said: “I’m completely puzzled. Almost invariably when you introduce anti-dumping measures, you claim that what you’re doing is consistent with the WTO. So to ask Geidt’s opinion on an anti-dumping duty, it’s totally bizarre. He has no expertise in this area. You would ask Suella Braverman [the attorney general] whether it’s legal.” One government insider said: “I don’t know what his involvement is in this: he’s not a lawyer.” They added that it seemed “particularly helpful” to the government that the issue at stake – steel tariffs – was one where Labour backed the government’s stance. Jacob Rees-Mogg, the Brexit opportunities minister, told the BBC’s Newsnight that Geidt had resigned “over an issue relating to protecting the British steel industry,” adding, “the prime minister is backing British industry and he’s right to be doing so”. Johnson said in his letter that he had made the decision to refer the matter to Geidt following advice from the Trade Remedies Authority (TRA) – an independent body set up after Brexit. However, the TRA later issued a statement insisting it had provided analysis, but not made any recommendations – and that ministers had “called in” the issue of steel tariffs, so the decision now lies entirely with them. Both Johnson and the business secretary, Kwasi Kwarteng, are keen for the tariffs to continue. “If you drop the safeguards the UK effectively becomes a landing zone for Chinese steel dumping, if the EU keep theirs,” said a source in Kwarteng’s department.