Dominic Cummings is expected to make a public statement later amid growing calls for the prime minister’s most senior adviser to resign for travelling during lockdown.
Boris Johnson is also facing mounting pressure from his own MPs to order an official investigation into his chief aide.
And police have been asked to establish the facts about Mr Cummings’s movements in Durham, when the country was being asked to stay at home.
Mr Cummings is expected to make a personal statement later this afternoon.
Mr Johnson’s own MPs are concerned a number of key questions still linger over the controversy.
The government has admitted Mr Cummings drove 260 miles to stay near family in county Durham while the country was in lockdown.
But they insist he was right to do so as he was seeking childcare for his young son.
Ministers, including the prime minister, have sidestepped questions about whether or not he took a sightseeing trip while he was in Durham, however.
Questions also remain over whether or not Mr Cummings stopped during the four hour car journey from London.
Mr Johnson had hoped his public support for Mr Cummings last night would draw a line under the row.
But he is facing calls from his own MPs to order a Whitehall investigation to establish the facts of the case.
More Tory MPs have also come out publicly today to call for Mr Cummings to go.