One of Boris Johnson’s most senior backbenchers and a top government scientist today joined calls for a short national circuit-breaker lockdown amid warnings of 690 daily coronavirus deaths within a fortnight.

The Prime Minister has hitherto resisted demands from Labour leader Sir Keir Starmer and regional mayors to impose a nationwide lockdown and is pressing ahead with a targeted battle plan of local restrictions. 

More than 28 million people are now living under tighter measures, with people in London among those plunged into Tier 2 last night which bans two households from meeting indoors.  

But former health secretary Jeremy Hunt this morning ratcheted up pressure on the PM to go further and indicated his support for a short…