Britain's Queen Elizabeth will not attend the opening of parliament on Tuesday as she has had a recurrence of issues with her mobility, Buckingham Palace said on Monday, adding her son Prince Charles would set out the government's agenda instead.

The 96-year-old British monarch has been forced to cancel a number of public engagements since being hospitalised last October for an unspecified illness, although she has continued to carry out many of her duties virtually.

"The queen continues to experience episodic mobility problems, and in consultation with her doctors has reluctantly decided that she will not attend the State Opening of Parliament tomorrow," Buckingham Palace said in a statement.

"At Her Majesty's request, and with the agreement of the relevant authorities, The Prince of Wales will read The Queen's speech on Her Majesty's behalf, with The Duke of Cambridge also in attendance."

The Palace declined to give details of Elizabeth's ailment but a source said it was related to the issues she had suffered last year, saying her decision to pull out of the parliament opening had only been made on Monday.

It comes as Britain will hold four days of celebration in June for the queen, the world's eldest and longest-reigning monarch, to mark her 70th year on the throne.