The BRC said that some £4.4bn will have been spent from Monday this week up to tomorrow, with a further £3.6bn spent over the four-day Easter weekend.
BRC director general Stephen Robertson said: "The early Easter could be a mixed blessing. Overall, Easter is retailers' second most important sales season, though for some it matters even more than Christmas. With personal finances under pressure and evidence that customers are cutting back on non-essentials, retailers are eager for the Easter boost. But the predicted poor weather is likely to mean a March Easter is weaker than last year's warm and sunny April."
Mike Watkins, senior manager, Retailer Services, Nielsen, said: "This year it's difficult for retailers to know how strong Easter trading will be with consumer spending being squeezed. Easter growths are considerably slower in a number of sectors compared with the first two weeks of Easter in 2007. It's possible that any last-minute rush to buy food and indulgences will be less marked than last year when the weather was unseasonably warm."