Pubs, bars and restaurants in Tier 3 (very high) local lockdown areas have seen sales drop by almost two-thirds since the restrictions came into force, according to CGA data.
Businesses in the top level regions reported a decline in daily sales of 60%-62% from last Thursday to Saturday.
Liverpool entered Tier 3 on 15 October, followed by Lancashire last weekend.
Under Tier 3 restrictions pubs and bars can only remain open if they serve alcohol with ‘substantial meals'.
This led to a 73% decline in year-on-year drinks sales last Saturday in Tier 3 areas, with spirits sales down 83%.
Though all hospitality venues are able to remain open in Tier 2, businesses in this ‘high' level saw sales drop 46%-54% over the three-day period.
Those in Tier 1 (medium) also reported a 22%-28% decline as tighter restrictions came into force across the country.
"These figures lay bare the instant and seismic impact of the new tiered system on hospitality," said CGA group chief executive Phil Tate.
"The loss of nearly two-thirds of daily sales in top-tier areas like Liverpool is catastrophic for local operators, and with Greater Manchester now set to join them, there is a lot more hardship to come.
"It is also alarming to see a sharp drop-off in second-tier areas, where businesses are battling relentless challenges without financial support. Urgent government help is needed if businesses and jobs are to be sustained through this rapid downturn in sales."
Hospitality businesses in Manchester told The Caterer trade had already been ‘decimated', with footfall dropping 60% and barely any weekday customers in central areas.
There are growing calls for the government to offer a more substantial support package to businesses and workers, including matching the 80% furlough scheme introduced during the national lockdown.