At the time Dominic Cummings had coronavirus symptoms, there was only a limited set of reasons for which people were allowed to leave their homes.
And the advice for anyone was – and is – not to leave home at all for at least seven days.
Remember there have already been other senior figures involved in tackling the pandemic who have had to resign for breaching lockdown restrictions.
A source close to Dominic Cummings is insistent that he didn’t break the rules.
But for those at the top to be perceived to even be stretching the rules is damaging.
Along with triggering accusations of hypocrisy, it risks prompting people to question why they should be following the rules, if those involved in imposing them are not.
The Scottish National Party’s Westminster leader Ian Blackford said Mr Cumming’s position was “untenable” and that the prime minister has “serious questions” to answer about the reports.
“nothing in the guidance that justifies travelling more than 250 miles”.
“Dominic Cummings has to do the right thing, and if he doesn’t resign, Boris Johnson should sack him and he should do that this morning,” Mr Blackford said.
“When you have a situation that at the highest level of government that [lockdown] rules aren’t being followed then I think people expect action to be taken.”
Meanwhile, Dave Penman, general secretary of the FDA, the union that represents senior civil servants, said the prime minister was responsible for the actions of his chief aide, and called for Mr Johnson to explain reports that Mr Cummings broke lockdown rules.
He told BBC Radio 4’s Today programme that “essentially, when he [Mr Cummings] says or does something he is doing it in the prime minister’s name”.
It comes after other high-profile figures involved in tackling the pandemic have resigned for breaching lockdown restrictions, including Scotland’s former Chief Medical Officer Catherine Calderwood and leading scientist Prof Neil Ferguson.
Dr Calderwood resigned in April after making two trips to her second home during the coronavirus lockdown.
While Prof Ferguson quit as a government adviser on coronavirus after it was reported that a woman he was said to be in a relationship with visited his home in lockdown.
The PM’s chief aide Dominic Cummings is facing calls to resign after it emerged he travelled from London to his parents’ home in Durham with coronavirus symptoms during lockdown.
Mr Cummings and his wife, who was also unwell, stayed at his parents’ home while self-isolating.
Labour demanded No 10 provided a “swift explanation” for Mr Cummings’ actions.
A source close to Mr Cummings denied a breach of the coronavirus rules, saying the couple needed childcare help.
They told the BBC’s political editor Laura Kuenssberg that the couple had stayed in a separate building at the property.
Downing Street declined to comment on Friday night, after the Guardian and the Daily Mirror newspapers first reported Mr Cummings had made the more than 260-mile journey.
The government has ordered anyone with coronavirus symptoms to self-isolate at home and not leave – even for essential supplies – for seven days.
Meanwhile, Prime Minister Boris Johnson said in March that children should not be left with older grandparents or older relatives “who may be particularly vulnerable or fall into some of the vulnerable groups”.
A Labour spokesman said: “If accurate, the prime minister’s chief adviser appears to have breached the lockdown rules. The government’s guidance was very clear: stay at home and no non-essential travel.
“The British people do not expect there to be one rule for them and another rule for Dominic Cummings.”
Mr Cummings has attended meetings of the Scientific Advisory Group for Emergencies (Sage) – the scientific body which gives independent advice that shapes the government’s coronavirus response.