The government’s own scientific advisers warned that its 10pm curfew on pubs, bars and restaurants would only have a “marginal impact” on the spread of coronavirus.

Documents published on Monday from the government’s Scientific Advisory Group for Emergencies (Sage) show that experts dismissed the idea of a curfew exactly a week before one was implemented across England.

In a document from 17 September, seven days before the 10pm curfew came into force, Sage wrote: “Curfews likely to have a marginal impact. Low confidence.”

The document was published on Monday just hours after prime minister Boris Johnson announced details of a new three-tier lockdown system in England.

Watch: Boris Johnson announces three-tier lockdown

The 10pm curfew has been criticised by scientists, as well as politicians in the North of England, who have doubted its