Boris Johnson has led the UK through a disastrous pandemic in which more than 127,000 people have died, and unprecedented constitutional change after leaving the EU.
Yet despite the seismic nature of those events, a row over how the refurbishment of his Downing Street flat was initially funded looks like it may become the biggest scandal of his premiership so far.
That’s after the Electoral Commission dramatically announced on Wednesday that it will be investigating the matter, saying there are “reasonable grounds to suspect that an offence or offences may have occurred”.
Questions are also being asked over whether Johnson broke the rules set out in the ministerial code.
Watch: Keir Starmer brands Boris Johnson ‘Major Sleaze’ during PMQs row
Here, Yahoo News UK explains what the code is, and if the prime minister could be in trouble.
What is the ministerial code?
It’s a set of rules and principles outlining the standards of conduct for government ministers (follow this link to view the full ministerial code).
If a minister breaches it, they are usually expected to resign, or be sacked, though the code is not legally binding.
In the context of the flat refurbishment row, Johnson has been accused of initially using a loan from the Conservative Party to fund the renovation.
If that is the case, it would be in contravention to section 7.20 of the code, which reads: “It is a well-established and recognised rule that no minister should accept gifts, hospitality or services from anyone which would, or might appear to, place him or her under an obligation.”
In the foreword to the code, written by Johnson himself in August 2019, the PM also says there must be “no actual or perceived conflicts of interest”.
Meanwhile, the code also requires a list of ministers’ interests to be published “twice yearly”. However, one hasn’t been published since July last year.
So could it land Johnson in trouble?
No. While any breach would put the PM under massive pressure to resign, Johnson will retain the power to exonerate himself as the “ultimate arbiter” of the code.
It follows the government's appointment of Lord Geidt as a new independent adviser on ministers’ interests.
Johnson's official spokesman said on Wednesday that the PM had concerns that an independent adviser with the power to launch probes could be drawn into an investigation with “trivial or vexatious complaints”.
“So he will remain the ultimate arbiter of this,” the spokesman said.
Asked if that means Johnson could reject any findings on himself, the spokesman said: “The PM will remain the ultimate arbiter of this, yep.”
Johnson, furthermore, has already shown he is willing to ignore breaches of the ministerial code.
In November, after a probe into home secretary Priti Patel found her conduct “amounted to behaviour that can be described as bullying”, Johnson stood by her – prompting his then-ministerial standards adviser, Sir Alex Allan, to resign.
So, if Johnson does find his position at risk due to the refurbishment row, it won’t be due to the ministerial code.
Watch: Watchdog launches formal investigation into Boris Johnson’s flat refurbishment