All parts of the market have been hit hard, it says, with the slowdown starting in February and continuing for the first half of the month before the total shut down on 20 March.
Restaurant groups reported a 56% fall in like-for-like trading compared to March 2019, with bar chains down 60% and managed pub operators reporting a 58% fall in trade.
London trading was down 60%, with outside the M25 down 57%.
“The drop in sales that began in February and escalated in the next month, means that even by the end of March, the eating and drinking out sector had fallen into year on year decline, down 4.1% on the previous 12 months, with London down 3.7%,” says Karl Chessell, director of CGA, the business insight consultancy that produces the Tracker, in partnership with The Coffer Group and RSM.
“With shut down wiping out April sales, apart from a small amount of delivery income, and May likely to be the same, the devastating effect on the market is self-evident.
“Even if there is an early easing of restrictions, which is far from certain, reopening of the market will almost certainly be phased and gradual.
“We are looking at a substantial loss of revenue right across the sector.”
Delivery, meanwhile, accounted for 7.4% of sales among the casual dining groups in the Tracker cohort, up from 5.5% in January.
“Although there has been growth in delivery and there is plenty of evidence to suggest more consumers are turning to delivered food during the lockdown, the picture is patchy,” says Chessell.
“As well as more companies establishing delivery options, there are also a number of major players that have closed down their delivery businesses altogether for safety reasons.”
While government support has helped the sector so far, more needs to be done to protect the 3.2 million jobs of those who work in hospitality, according to Paul Newman, head of leisure and hospitality at RSM.
"At a time when cash is so desperately needed to meet the upfront wages for furloughed staff, most operators are still struggling to access the Coronavirus Business Interruption Loan Scheme under current lending criteria.
"Great uncertainty remains not only as to the extent of the current shutdown, but also as to what the lifting of lockdown might look like. More support is needed with property related costs and this includes support for landlords themselves who remain liable to pay business rates for empty sites."
Due to the effect of the lockdown, the number of companies taking part in the March data collection was smaller than usual, totalling 44, but still representing operators across all parts of the sector, says the company.