Dame Quentin Bryce visited the Queen at Buckingham Palace last July, Sir Peter Cosgrove was invested at Balmoral in Scotland in August, and Dame Marie Bashir received the order's insignia in an audience with the monarch at Buckingham Palace in July. Prince Andrew, the Duke of York, has been keeping Buckingham Palace busy with his own controversy. Credit:Getty Images However, when asked when and where the ceremony would take place between the Queen and her husband, Buckingham Palace referred all questions back to the Australian government, saying it would not give any "guidance" on matters of process. "The Queen acts on the advice of the Australian government on any appointment to the Australian order, just as she would act on the advice of the UK government for any British Knighthoods. We would direct you to the Australian government for further guidance on your below questions," a Palace spokesperson said. The Palace also declined to answer whether it was common practice for a royal to acknowledge, or express thanks, for honours and honorary positions bestowed by foreign governments or organisations.

The Duke of Edinburgh has made no public comment on his appointment (and we are unlikely to find out whether he has thanked his wife in private) – his most recent comments are about engineering, in an article in New Scientist. Under fire ... Tony Abbott has faced a backlash for recommending the Duke of Edinburgh, Prince Philip, for knighthood in the order of Australia. And the Palace press office has not reflected it in their press releases or Twitter feeds. This has led to speculation in the 'electronic graffiti' of social media that the Palace wants to stay out of a fight that has turned embarrassingly political – though another theory is that they have been too busy dealing with the scandal enveloping the Duke of York. The knights and dames in the order of Australia were reinstated by 'letters patent' amended by the Queen under the great seal of Australia at St James' Palace (the most senior palace of the Sovereign), on March 19 last year.

According to those letters patent, appointments to the order as knight or dame are made "with the approval of the Sovereign on the recommendation of the Prime Minister, by Instrument signed by the Governor-General and sealed with the seal of the order". There is no explicit instruction that the honour must be invested by the Queen in person. Technically, it seems, it could be signed by the Governor-General and sent to the Duke in the post. Or not. However, the Queen has conferred titles on her husband in the past – and did it in person. Most recently, she formally presented him with the title and office of Lord High Admiral of the Navy, as a present to mark his 90th birthday. The ceremony took place at Admiralty House in Whitehall in November 2011, four months after it was announced. In the UK honours system, recipients of an honour are members of the order from the moment it is announced. The 'investiture' is a subsequent, ceremonial element.