The parents of a six-year-old boy who was treated for a brain tumour at the Royal Alexandra children's hospital in Brighton are joining a fund-raising day.

Freddie Smith has been a regular visitor to the hospital for the last three years after he was diagnosed with a brain tumour.

His parents, Carey and Alison, are backing this year's Wrong Trousers Day on July 4, which aims to raise much needed money for children's hospitals and hospices across the UK.

The day marks the launch of the newly-formed charity, Wallace and Grommit's Children's Foundation.

The charity, based on the popular animated characters, aims to raise millions of pounds for about 20 hospitals and hospices.

Celebrities supporting the cause include former Olympic gold medallist and Steyning resident Sally Gunnell, Russell Crowe, Kevin Spacey, Kenneth Branagh, Carol Vorderman, Anthony Minghella and Claire Sweeney.

Participants can wear shorts, pyjama bottoms or even jeans, as long as they are "wrong".

Mr Smith, from Henfield, said: "We are so lucky to have a specialist children's hospital in our community.

"When Freddie was nearly four, he began falling over a bit more than usual and having bad headaches. The headaches persisted and he started complaining of giddiness."

"He was seen by Ann Davidson at the Royal Alex who ordered an urgent scan and was able to diagnose a cancer tumour in his brain.

"Dr Davidson arranged for him to have brain surgery at King's College Hospital in London within 36 hours," said Mr Smith.

After recovering from two operations to remove the tumour Freddie was transferred to the Royal Marsden Hospital in Sutton, Surrey.

He had three months of radiotherapy there, followed by a year of chemotherapy undertaken jointly by the Marsden and the Alex.

Mr Smith said: "When a child has cancer, the first priority is to save his life but treatment and care doesn't end there.

"The Royal Alex has also helped Freddie with many secondary issues, such as blood transfusions, kidney problems, hearing loss, weight loss and physiotherapy as well as providing acute care when he had an infection during chemotherapy over Christmas."

For more details about the campaign go to www.wrongtrousersday.org