A children's voluntary worker walked out of a supermarket in disgust after staff refused to sell him 30 packets of biscuits - because he was only allowed ten.

Stephan Bennett went into Tesco in Burgess Hill to buy snacks for a group of special needs children.

He loaded his trolley with 30 packets of biscuits and 20 bottles of dilutable orange juice.

When he got to the checkout, he was told he could only buy a maximum of ten of each item.

Mr Bennett, who lives in Brighton, said: "The check out staff said it would affect the supermarket's stock levels. I thought it was absolutely appalling. I had no idea rationing was still on."

Mr Bennett, a volunteer with a group which takes children from the Chanctonbury Play Scheme, near Steyning, on day trips, said he left the trolley at the cash till and walked out.

He now plans to complain to Tesco chiefs about the rule.

He said: "I only wanted a few snacks for the kids. We take up to 100 children at a time on the trips such as swimming or balloon workshops.

"They usually bring their own packed lunches but we provide them with soft drinks and additive-free biscuits or cakes.

"I thought the whole idea of having a supermarket was to sell their stock.

"This rule is ludicrous and must affect large families in the area who want to stock up but can only buy ten of any item.

"We could turn up at the store with 100 kids, each buying their own packet of biscuits. But that wouldn't be fair on them or their parents."

A Tesco spokesman said the ten-item rule was part of its nationwide policy to deter bulk buying.

He said: "The policy is aimed at stopping cash-and-carry shoppers.

"It is at the discretion of each shop manager and depends on individual circumstances.

"If there is enough stock on the shelves, it doesn't make a much of a dent. It becomes more serious when there is not much stock.

"We have had people who just cleared the shelves when they saw a good price. We want all our customers to be able to enjoy our whole range of products.

"Thirty packets of biscuits and 20 litres of orange juice would have severely depleted the stock.

"If the gentleman had given us a bit of warning we would have had no problem ordering in the items."

The spokesman said people wanting to buy more than ten of any one item at Tesco should phone the store or go to the customer help desk in the supermarket at least two days in advance to tell them what they planned to buy.