A shop assistant suffered "excruciating" pain after being given an almighty slap on the backside by a drunken male customer.

Blackburn magistrates heard the blow aggravated an existing sciatic condition suffered by Joan Ingram, who was working at Tesco in Clitheroe at the time.

After the hearing unemployed building worker John Andrew Stevenson said he wished to apologise publicly to Mrs Ingram for what he had done.

"I deeply regret what I did, I was drunk but that is no excuse," said Stevenson, 42, of Lowergate, Clitheroe.

"I have known the lady in question for two or three years from going into Tesco, we always speak and there has never been any trouble before. I went to the shop to apologise but the security staff wouldn't let me in. I just hope the lady reads this and can accept how sorry I am."

But his apology cut no ice with Mrs Ingram, 58, who said she would rather have nothing more to do with her assailant.

"He's barred from the store and as far as I am concerned that is the way it will stay," said Mrs Ingram. "I've been married for 40 years and my husband has never raised a hand to me and I don't have to tolerate that sort of behaviour from a customer."

Stevenson pleaded guilty to assault. He was given a conditional discharge for 12 months and ordered to pay £100 compensation.

John Wood, prosecuting, said Mrs Ingram was working near the check-out at about 5pm when she felt an "almighty crack" on her bottom.

"In her words she felt excruciating pain and was sick with shock," said Mr Wood. "She realised someone had struck her but didn't know how or with what. She turned round to see the defendant laughing as he wandered off."

Stevenson told police he thought Mrs Ingram would take it as a joke.

Deborah Morgan, defending, said Stevenson was a regular shopper at the store and had never caused any trouble before.

"He clearly didn't know she suffered from sciatica which accounted for the pain she felt," said Miss Morgan.