THE mother of Potteries pop star Robbie Williams is critical but stable in hospital after undergoing major heart surgery, it was reported today.

A national newspaper claimed Robbie, aged 34, had returned to Britain from Los Angeles to be with mum Jan, who has had a heart bypass operation.

The Sun said that Burslem-born Robbie will be unable to visit his mother until she is out of intensive care. However, he would spend Christmas Day in hospital with her as she recovers, the newspaper said.

Today, Robbie's sister Sally told The Sentinel that the star hadn't yet returned to Britain.

A source told The Sun: "Like any patient who has undergone major heart surgery, Jan's not out of the woods yet. She is in a critical but stable condition, but that's normal for such a complex procedure."

Jan is a high-profile figure in North Staffordshire and is a dedicated charity worker.

Besides a leading role with Robbie's Give It Sum fund, she has supported The Sentinel's Our Heroes awards and countless other community initiatives.

According to The Sun, Jan was admitted to a private hospital in Cheshire on Saturday. She is believed to have had her operation yesterday after Robbie had jetted back to see her.