Convenience store owners need to carry on investing in their businesses through a worsening economic crisis, says the head of Britain’s largest symbol group.

Spar UK managing director Jerry Marwood told retailers at AF Blakemore’s conference to expect conditions to get far worse before they get better. Speaking ahead of Tuesday’s Budget, he said: “Convenience stores have been resilient and we can keep it that way, but we have to be ready for what’s coming.

“The effects of the Budget are going to be a shock to us all. They will change our idea of what good looks like. The economic climate is not going to improve any time soon, and there will be casualties. It’s our job to make sure we are not among them.”

Marwood said investment was the key to survival. “Never stop investing,” he said “Don’t consolidate – Woolworths had strong aspects to its business, but failed to evolve. Be prepared to spend to improve every department of your store.”

He also recommended that stores “sell, sell and sell again”. “Instil it into the nature of your business – don’t let processes squeeze the selling out of you.”

Following the government’s lead and cutting costs were also essential, he added. “Reduce your costs, and when you’ve done that start doing it all over again,” he advised.

Pointing out that customers’ main concern in the future would be a fair price and that the price agenda would be set by the Big Four, Marwood warned that “there is no money in putting prices up. Set a reasonable price point and make sure everybody knows it.”

Blakemore’s Dennis Evans told the conference the wholesaler would help its Spar members through “extremely difficult and changing times” with an additional £1m investment in reducing the wholesale prices of big volume lines, a saving worth an average of £5,000 a year to each store, he said.