The package includes making the Job Support Scheme, which replaces the current furlough system, more generous. There will also be grants of £2,100 available for firms in Tier 2 areas of England, including London, primarily aimed at helping hospitality and leisure venues which have seen takings plummet due to a restrictions on households mixing.
It comes as Prime Minister Boris Johnson is set to hold press conference at 4pm regarding the coronavirus situation. Mr Sunak and chief scientific adviser Sir Patrick Vallance will also be answering questions at the event.
Meanwhile, figures show that just 59.6 per cent of close contacts of people who tested positive were reached through the Test and Trace system, its worst performance yet.
Follow our live updates here...