The PM’s chief adviser Dominic Cummings is to make a public statement and take questions over allegations he broke coronavirus lockdown rules.
Mr Cummings is facing calls from Labour and some Tory MPs to quit or be fired.
He travelled 260 miles with his family to be near relatives when his wife developed Covid-19 symptoms.
Boris Johnson insists his aide acted legally and within guidelines – but critics say the government’s lockdown message has been undermined.
The prime minister made a statement on Sunday in an attempt to draw a line under the row – but Conservative MPs have continued to call for Mr Cummings’ dismissal.
Mr Cummings has been under fire since the Guardian and Daily Mirror reported that he had been seen in County Durham, at his family’s farm during lockdown.