Labour leader Jeremy Corbyn will not be attending a meeting of the Privy Council because of “prior commitments”, his spokesman says.

It would have been the first chance for Mr Corbyn to be sworn in to the ceremonial group of advisors.

Opposition leaders can receive briefings from the security services through their membership of the group.

Tory MP Alan Duncan said Mr Corbyn had to decide whether he was a serious political figure.

Last month Mr Corbyn, a lifelong republican, refused to say whether he would kneel to the Queen as part of the traditional swearing-in ceremony.

His spokesman said the Labour leader could not make Thursday’s meeting because of prior commitments and had sent his apologies.The Privy Council dates from the court of the Norman kings 

There were separate Privy Councils in England and Scotland prior to the 1707 Act of Union 

It convenes, on average, about once a month – and has met six times so far this year 

The quorum required for each meeting, with a few exceptions, is three plus the Lord President (currently Chris Grayling)

The Privy Council’s role is to advise the monarch of the day in carrying out their duties, such as the exercise of prerogative powers and other functions assigned to them by Acts of Parliament.

Much of its business is rather routine and is concerned with obtaining the monarch’s formal approval to orders which have already been discussed and approved by ministers or for the arranging for the issuing of royal proclamations. Queen Anne was the last monarch to refuse an order.

The council has about 600 members – although only a handful usually attend the monthly meetings.

Prime Minister David Cameron was sworn in as a Privy Counsellor in March 2006, three months after he became leader of the Conservatives.

Mr Duncan, who is also a Privy Counsellor, said Mr Corbyn seemed to want to put politics above the Queen.

He also added that the new Labour leader needed to decide if he wanted to be a serious political figure or a perpetual rebel.