NEARLY SIX months have passed since the Daily Mirror first reported that parties had been held in Downing Street during Britain’s covid-19 lockdown. At least 16 such gatherings were held across government premises. The Metropolitan Police have issued 50 fines for breaches of lockdown laws: the recipients include Boris Johnson, the prime minister, his wife, and Rishi Sunak, the chancellor. Mr Johnson thus became the first prime minister to be found to have broken criminal law in office. His ratings, as well as Mr Sunak’s, have collapsed. More fines may follow, quite possibly for the prime minister.

Yet Mr Johnson remains in office. He is determined to fight the next election as the leader of the Conservative Party. That he can do so underlines an enduring feature of British politics: outside of an election, only MPs can remove a prime minister who does not want to leave. Beyond that, despite an elaborate array of bodies tasked with policing standards in public life, the means of sanctioning an errant prime minister are weak. Mr Johnson has weaved past them all.

Civil servants cannot check Mr Johnson. The prime minister at first asked Simon Case, the cabinet secretary and head of the civil service, to investigate the reports of parties. He recused himself as it emerged he too had taken part in such events; the work fell instead to Sue Gray, a veteran civil servant. Her interim report concluded that the gatherings “should not have been allowed to take place or to develop in the way that they did”. A fuller report is due once the police have concluded all their probes. Yet as a civil servant, Ms Gray has no power to sanction Mr Johnson.

Ministers are supposed to check themselves. Those who violate the Ministerial Code—the rules by which ministers should abide—are expected to resign. Two clauses are pertinent in Mr Johnson’s case. One states that there is an “overarching duty on Ministers to comply with the law and to protect the integrity of public life”. The other says that ministers “who knowingly mislead Parliament will be expected to offer their resignation to the Prime Minister”. The prime minister can refer cases of a breach to his independent adviser on ministerial interests, Lord Geidt, formerly the queen’s most senior aide. Yet any decision lies with the prime minister, as “the ultimate judge of the standards of behaviour expected of a Minister”. When the wrongdoer is the prime minister, he judges himself.

Some officials can express an opinion on the prime minister’s behaviour but not do anything about it. One example is the chairman of the Committee on Standards in Public Life, which was a product of the sleaze scandals that buffeted the Conservatives in the 1990s. The incumbent Jonathan Evans, is a former head of MI5 and a ramrod-straight character. He has become increasingly alarmed at Mr Johnson’s government, which likes to argue that only voters can say what is right or wrong. Mr Evans says this is like letting the crowd referee a football match. Although he is empowered to advise the prime minister on ethics, his powers stop at advice.

Opposition MPs want to bring Mr Johnson into line. On April 20th Labour proposed having the Privileges Committee, another parliamentary body, examine whether Mr Johnson had lied about the parties. The next day MPs nodded this motion through, meaning Mr Johnson has notched up another unfortunate first: the only prime minister to be investigated over claims that he intentionally misled Parliament. But even if the committee reaches the conclusion that he did, Mr Johnson can simply choose not to resign.

With a clear majority in Parliament, only Conservative MPs hold a true threat of sanction over Mr Johnson. If he loses the confidence of the Commons as a whole, his government falls. Within the Tory party, Mr Johnson would face a confidence vote if 15% of its MPs (ie, 54 of them) call for one. He would have to win that vote, in which MPs would be offered a binary choice between keeping him or binning him.

The British constitution, despite its apparent mystery and complication, is in fact a simple thing. All roads of the executive branch lead to Mr Johnson: ministers and civil servants answer to him. He, in turn, is accountable directly to Parliament, which in effect means his colleagues in the Conservative Party, given its large majority. It is they alone who decide. By their hand, an errant prime minister can meet a rapid and brutal end—or be propped up indefinitely. ■