Royal wedding countdown begins as Kate Middleton attends rehearsal at Westminster Abbey

Miss Middleton was said to be “relaxed and excited” as she was guided through the service by the Dean of Westminster, the Very Rev Dr John Hall.

The half-hour “walk-through” for the bridal party also included Kate Middleton’s sister Pippa, who will be maid of honour, and the bridesmaids and page boys.

It came as St James’s Palace issued a minute-by-minute timetable of the wedding day on April 29, which shows that Prince William will have to wait at the Abbey for 45 minutes for the arrival of his bride-to-be.

The royal party managed to slip into the Abbey at 8.45am via a side entrance away from the gaze of tourists, who were told the building was temporarily closed for the rehearsal.

A witness inside the Abbey said Miss Middleton, who was dressed casually, arrived with Prince Harry, who will be best man.