Except on state occasions,pedestrians will have free roam of the square, with its panoramic views of St James's Park and the back of Downing Street.
Ending car parking on the Parade was recommended by the Royal Parks Review Group in 1993. It said it was "quite unacceptable that so fine a space ... should be used in this way".
In June 1994, The Independent revealed that the plan had been quashed by John Major and senior cabinet ministers because of pressure from Downing Street civil servants.
At the time, about 800 people were entitled to park on Horse Guards. The number has now been cut to about 250.