This season’s FA Cup final on 3 June will revert to a 15:00 BST kick-off for the first time in 12 years.
The match between Manchester United and Manchester City at Wembley was expected to begin between 16:45 and 17:30.
But London’s Metropolitan Police has categorised the derby match as high risk and objected to the later kick-off times on security grounds.
It is set to be the first time the game has started at 15:00 since Manchester City beat Stoke in 2011.
It will be the first FA Cup final between the sides and last season, Liverpool and Chelsea both received allocations in excess of 30,000 for the game.
The earlier kick-off time should make travelling away from London easier for the fans, with the last direct train from the capital to Manchester on 3 June scheduled to depart at 21:01.
Tuesday’s Premier League game between Arsenal and Chelsea was rescheduled at less than three weeks’ notice following Met Police objections.
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