Sir Mark Sedwill gave the go ahead to a press conference held by Dominic Cummings in the Downing Street rose garden, he has told MPs.
In a letter copied to SNP Westminster leader Ian Blackford and shadow Cabinet Office minister Rachel Reeves, the cabinet secretary said he believed it was “appropriate” for Cummings to explain his actions on government premises given the recent controversy over his conduct in his official role.
The special adviser told reporters on Monday that he had taken his family to stay on his parents’ property in Durham after his wife contracted coronavirus to ensure there was childcare available for his son if he became ill.
He also admitted to taking a further 30-minute journey to Barnard Castle – saying he had wanted to test that his eyesight was good enough to drive back to London.
Durham police said yesterday that Cummings "might" have broken lockdown rules with the second journey, which the spad took after contracting and recovering from coronavirus.
It is unprecedented for a special adviser to give a press conference about their own conduct on Downing Street grounds.
In his letters to the two MPs, Sedwill said the statement had been authorised by the prime minister under the special advisers’ code of conduct “given the continuing public interest in this matter”.
“As the event related to his conduct in his official role, I considered it appropriate for the No.10 press office to facilitate it on government premises,” he said.
Sedwill was responding to letters sent by the two MPs, both sent on 23 May, raising concerns about Cummings’s conduct.
Reeves wrote to the cab sec on 23 May after media reports that Cummings had travelled during lockdown, calling on the Cabinet Office to launch an “urgent investigation” into the matter.
The shadow minister questioned the arguments put forward by No.10 backing the spad, including the claim that it was “essential” for him to travel to ensure the wellbeing of his young child. Reeves said the journey breached the PM’s instructions to “stop non-essential contact with others and to stop all unnecessary travel”.
She put a series of questions to Sedwill about when Boris Johnson was informed about Cummings’s journeys, why No.10’s official spokesperson said Cummings was self isolating “at home” with Covid-19 on 31 March, and if his actions had breached lockdown rules or the spad code.
Blackford’s letter meanwhile called for an investigation into Cummings’s “rule-breaking and the Tory government’s cover-up”.
He also asked several questions, including why the aide was not sacked or asked to resign when the events occurred.
In his letter – which came after Johnson told MPs this week that he was not convinced a public inquiry would be a "good use of official time" – Sedwill said the prime minister had “accepted Mr Cummings’s explanation of his conduct”.
The cab sec added that it was ultimately for Durham Constabulary to determine whether Cummings had breached lockdown regulations.
The force said that while it did not consider the journey to Durham to have broken the rules, in the case of the Barnard Castle trip “there might have been a minor breach of the regulations that would have warranted police intervention.”
“Durham Constabulary view this as minor because there was no apparent breach of social distancing,” it said in a statement yesterday.