The Duke of Edinburgh Prince Philip has already joked about his retirement after announcing he will step down from royal duties later this year.

The 95-year-old prince's decision to no longer carry out public engagements from August has the full support of Queen Elizabeth II, Buckingham Palace said in a statement last night.

Buckingham Palace made the announcement after hours of frenzied speculation, sparked by the Daily Mail UK, over reports senior royal aides were called to an emergency meeting with Lord Chamberlain, the most senior officer of the Royal Household and the Queen's private secretary Sir Christopher Geidt.

Just hours after the announcement, Prince Philip made a quip about the news at an Order of Merit service at the Chapel Royal in St James' Palace.

"I'm sorry to hear you're standing down," a guest was filmed saying before the prince, in his trademark quick wit, responded: "Well I can't stand up much longer."

At that service, Prince Philip also met with former Prime Minister John Howard, who was a guest alongside others including Sir David Attenborough.

Mr Howard told media he wished the retiring prince luck in the future.

"He's done an absolutely fantastic job," Mr Howard said.

"I'm a great fan of his and I think everybody appreciates what a wonderful consort he is.

"Good luck to him."

Former Australian Prime Minister John Howard (top, far right) at an Order of the Merit service with Prince Philip and Queen Elizabeth II after Buckingham Palace announced the duke's retirement from official duties. (AAP)

Prince Philip and Queen Elizabeth. (AAP)

Prince Philip will continue to attend previously scheduled engagements between now and August, both individually and with the Queen.

However, he will not be accepting new invitations for visits and engagements. The palace said he may still choose to attend some public events from time to time.

He will remain associated with the more than 780 organisations he is patron, president, or member of, but will no longer play an active role by attending engagements.

The Queen will continue to attend all her official engagements.

The couple, who is due to celebrate their 70th wedding anniversary in November, have been reducing their workload in recent years, passing on many responsibilities to son and heir Prince Charles, and grandsons, Princes William and Harry.

Both carried out official duties on Wednesday, with the Queen meeting Prime Minister Theresa May to formally agree to the dissolution of parliament ahead of June's election while Philip opened a new stand at Lord's Cricket Ground in central London.

Mrs May paid tribute to Prince Philip for his contribution to Britain and beyond, his "steadfast support" of Queen Elizabeth and for his patronage of hundreds of charities and good causes.