Dominic Cummings, the Prime Minister's chief adviser, has been taking part in meetings held by the secretive scientific group which advises ministers on coronavirus.
Mr Cummings was one of 23 attendees at a key meeting of the Scientific Advisory Group for Emergencies (Sage) on March 23, the day Boris Johnson announced the nationwide lockdown, according to a list leaked to the Guardian.
Ben Warner, a data scientist who worked on the Vote Leave campaign during the Brexit referendum, is also understood to have been present.
The revelation yesterday evening has raised "significant questions" about the independence of the scientific advice given by Sage. For the latest on the coronavirus pandemic, read our liveblog here A former