He also chastised members of the media for not standing two metres apart when gathered outside his London home.
Johnson and his most senior ministers have launched a major operation to save the polarising adviser from being forced out of Downing Street, arguing Cummings and his wife Mary Wakefield did not breach the rules because they were worried about the welfare of their young son and wanted to be near Cumming’s elderly parents and sister.
The rules at the time said anyone with symptoms must not leave their home under any circumstances and should not visit family members for any reason, however deputy chief medical Jenny Harries did tell a press conference held before the trip that a situation where two sick parents were unable to care for a child might warrant an “exceptional circumstance”.
Wakefield had coronavirus symptoms when the couple drove to Durham but Cummings did not, calling into question whether those exceptional circumstances existed at the time of the trip.
Cummings eventually developed symptoms and was bedridden for more than a week. Wakefield later wrote a piece for the Spectator describing the ordeal but never mentioned that they had left London for support. In the same piece, she wrote of emerging “from quarantine into the almost comical uncertainty of London lockdown”.
Downing Street officials also told political journalists at the time that Cummings was off work and self-isolating “at home”.
The scandal, revealed via a joint investigation by The Guardian and Daily Mirror, is a political danger for Johnson. The opposition and even some Tory MPs have said it shows one set of rules applies to political figures and another to the general public.
A senior member of the government’s Scientific Advisory Group for Emergencies, Professor Neil Ferguson, resigned earlier this month after he was caught breaking the lockdown rules to meet a woman he was in a relationship with.
Many of the same ministers who blasted Ferguson rushed to defend Cummings in a volley of tweets on Saturday that threaten to undermine the country’s public health messaging.
In an unprecedented defence of a government staff member by cabinet ministers, Chancellor Rishi Sunak, Health Secretary Matt Hancock, Foreign Secretary Dominic Raab, Attorney-General Suella Braverman and Cabinet Office Minister Michael Gove all said Cummings did nothing wrong.
“Caring for your wife and child is not a crime,” Gove said.
Johnson has given Cummings his “full support” however the situation is fluid and Cummings’ future is in doubt.
Acting Durham police commissioner Steve White on Saturday described Cumming’s conduct as “unhelpful” and “frustrating”.
“Given the whole ethos of the guidance and regulations issued from the government was to reduce the spread, regardless of the reason, by travelling to County Durham when known to be infected was unwise,” he said.
“To beat this crisis we need to be selfless as millions have been.”
Downing Street has claimed that “at no stage was Cummings or his family spoken to by the police about this matter” as was reported by The Guardian and The Daily Mail.
However a statement from Durham police said officers were told “that an individual had travelled from London to Durham and was present at an address in the city”.
“Officers made contact with the owners of that address who confirmed that the individual in question was present and was self-isolating in part of the house,” the statement said.
“In line with national policing guidance, officers explained to the family the guidelines around self-isolation and reiterated the appropriate advice around essential travel.”
The Labour opposition has called for an inquiry into the affair and said Johnson must answer details about whether he knew Cummings had moved to Durham during the lockdown.
“The lockdown rules were very clear: if you or anyone in your household was suspected of having COVID-19 you must immediately self-isolate and not leave the house,” the party said in a statement.
“However, the Prime minister’s chief adviser appears to believe that it is one rule for him and another for the British people. This will cause understandable anger for the millions of people who have sacrificed so much during this crisis.”
Bevan Shields is the Europe correspondent for The Sydney Morning Herald and The Age.