PRINCE William will marry Kate Middleton on Friday, April 29 next year at Westminster Abbey, St James's Palace has announced.

And the wedding - including the costs of the church service, music, flowers, decorations reception and honeymoon - will be paid for by the Royal family and the Middleton family.

The public will pay for associated costs like security.

Downing Street announced that the wedding day would be a public holiday. The extra day off on April 29 next year was agreed at Cabinet.

The Scottish Government is expected to make its own announcement in Holyrood shortly, as public holidays are a devolved matter north of the border.

Jamie Lowther-Pinkerton, private secretary to Prince William, said the couple chose Westminster Abbey for its "staggering beauty", 1,000-year Royal history and intimacy despite its size.

He told reporters in a briefing at St James's Palace: "The venue has long associations with the Royal family - it is in many ways the Royal family's church - and of course with Prince William personally."

The abbey was also the venue of William's mother's funeral. As a 15-year-old boy the Prince walked behind the coffin of Diana, Princess of Wales as it was led to the imposing church in September 1997.

Mr Lowther-Pinkerton said those planning the nuptials were very conscious of Britain's precarious finances.

"All parties involved in the wedding, not least Prince William and Miss Middleton, want to ensure that a balance is struck between an enjoyable day and the current economic situation," he said.

Mr Lowther-Pinkerton said William and Miss Middleton were "completely over the moon" about their engagement.

"They're now getting stuck into organising their wedding. They're giving us and the Household office very firm direction indeed."

Welcoming the announcement of the wedding date, Prime Minister David Cameron said: "The wedding of Kate and William will be a happy and momentous occasion.

"We want to mark the day as one of national celebration - a public holiday will ensure the most people possible will have a chance to celebrate on the day."