Published: 8:34 AM March 30, 2020 Updated: 6:03 PM September 17, 2020

Dominic Cummings is questioned by reporters as he leaves his home in London. Photograph: Sky News. - Credit: Archant

Boris Johnson's key adviser Dominic Cummings has self-isolated after showing coronavirus symptoms.

Cummings, who was reported last month to have said that it was 'too bad' if pensioners die from COVID-19 until he saw fresh science, is staying away from work after showing signs of the illness over the weekend.

The prime minister's official spokesman said the 48-year-old noticed symptoms of Covid-19 over the course of the weekend and had decided to self-isolate.

Asked whether Cummings had been tested for coronavirus, the spokesman added: 'I wouldn't expect that to be the case.'

The mastermind behind Vote Leave's messaging during the Brexit referendum was last seen running out of Number 10 shortly after Johnson posted a video message on Friday announcing he had tested positive, said to be concerned about catching the illness.

Chief Adviser to Prime Minister Boris Johnson, Dominic Cummings at a news conference inside 10 Downing Street, London. Photograph: Simon Dawson/PA Wire.

It raises fresh questions about whether officials in government were following its own guidelines during the coronavirus outbreak, after scientists claimed Johnson had flouted the rules.

Hancock, Johnson and England's chief medical office Chris Whitty have all self-isolated after COVID-19 reached Number 10.

David Frost, the UK's Brexit negotiator, and Scottish secretary Alister Jack also were forced into isolation.

Downing Street denied the claims from a newspaper report last weekend that the PM's top aide had been prepared to let the elderly die to protect the economy during the UK outbreak of coronavirus, and branded the Sunday Times report 'highly defamatory'.

A Tory election chief had been lined up to replace Cummings if he contracted COVID-19, an appointment that appeared to be made before the weekend.

You may also want to watch:

But No 10 played down any link between Levido's involvement and Cummings' illness.

'I'm not sure of a link between the two but Isaac has been working with us in Number 10 for the past week on the coronavirus response,' said the PM's spokesman.

'The two things aren't related. He is working on all aspects of the response.'

The spokesman said a 'number of people as contractors' had been brought in to Downing Street to 'bolster' the government's efforts in dealing with the crisis.