‘Show us the evidence’: Scientists call for clarity on claim that new Covid-19 variant strain is 70% more contagious

Boris Johnson was last night urged to publish clear evidence of the Covid data he used to cancel Christmas for millions.

The Prime Minister has warned the new variant of coronavirus may be up to 70 per cent more transmissible than previous strains and could overwhelm the NHS.

But last night one scientist demanded greater transparency over the number that shut down swathes of the UK.