THE policy of flying Union flags on royal birthdays is being re-examined after councils were ordered to do so on the Duke of York’s birthday.

Councils across Sussex confirmed they will be flying the flag on crisis-hit Prince Andrew’s birthday on February 19.

But only because it is flown outside their town and city halls every day.

This comes after an email, seen by The Sun, was sent to councils reminding them to fly the flag for Andrew’s 60th birthday.

It was said to have been sent from the private secretary to the Ministry of Housing, Communities and Local Government permanent secretary, Dame Melanie Dawes.

But critics said the order should be scrapped because of allegations that Andrew slept with Virginia Giuffre.

Downing Street said the matter was being looked into after critics branded the reminder “crass and offensive”.

Adur and Worthing Councils said it flies the flag every day and did was not aware of any letter being sent.

A West Sussex County Council spokesman said: “We fly the Union flag as our default flag. Therefore, the Union flag will be flying on February 19 as usual.”

Brighton and Hove City Council did not respond to a request for comment.

Prime Minister Boris Johnson’s official spokesman said: “This was an administrative email about long-standing policy.

“I understand DCMS (Department of Culture, Media and Sport) and the Royal Household are considering how the policy applies in changing circumstances such as when members of the royal family step back from their duties.”

A spokesman for the DCMS added: “This was an administrative email about a long standing policy. We are working with the Royal Household to consider how flag flying policy can be applied in changing circumstances, such as when a member of the Royal Family steps back from public duties.”

Andrew stepped down from public life in November after the fallout from his Newsnight interview.

He was accused of showing a lack of empathy for Jeffrey Epstein’s victims and of failing to show regret over his friendship with the disgraced financier.

His accuser, Ms Giuffre, says she and the duke slept together on three separate occasions, including when she was 17. Prince Andrew, who strenuously denies the allegations, is facing calls to talk to the FBI and US prosecutors.

Certain royal birthdays, including Andrew’s, are also marked by the ringing of bells at Westminster Abbey in central London.The re-examination of the flag-flying policy will not affect the Duke and Duchess of Sussex, who are also quitting royal duties amid the “Megxit” crisis.