The Queen will not attend the State Opening of Parliament as she continues to suffer with "episodic mobility problems", Buckingham Palace has said.

       Instead, the Prince of Wales will read the Queen’s Speech on her behalf, and at her request. The Duke of Cambridge will also attend.

       It will be just the third time that the Queen has not attended the event. On the two occasions she has previously missed it, the Lord Chancellor has delivered the speech.

       A palace source said the decision was taken on Monday, noting that she has continued to suffer with mobility problems since last autumn.

       A new Letters Patent authorised by Her Majesty specifically to cover the State Opening delegates the royal function of opening a new session of Parliament to Counsellors of State.

       In this instance, it enables her two heirs, Prince Charles and Prince William, to jointly exercise that function. No other functions have been delegated by Her Majesty. The Duchess of Cornwall will also attend but is not a counsellor of state.

       The Palace had previously stated that the Queen hoped to read her customary speech to open Parliament on Tuesday, but said final confirmation would be given on the day.

       Measures had been put in place to ensure privacy on her entrance and exit, with part of the walk shielded from cameras and the event pared back as much as possible.

       She had been expected to travel by car to the Houses of Parliament, wearing day dress without a heavy crown, and with the shortest possible route through the Palace of Westminster.

       This is a breaking story. More details to follow.