This was published under the 2010 to 2015 Conservative and Liberal Democrat coalition government
They will be married on Friday April 29 2011, at Westminster Abbey.
It was agreed by Cabinet that the day will be marked by a Bank holiday.
Bank holidays are devolved in Scotland. The Scottish government will be making proposals to the Scottish Parliament shortly.
The Prime Minister 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 bank holiday will ensure the most people possible will have a chance to celebrate on the day.
The costs of the wedding itself will be met by the Royal Household, with government meeting any wider security or transport related costs.