A decision by Foreign Minister Marise Payne to let the UK high commissioner's posting fall vacant during the Queen's Platinum Jubilee celebrations is "very disappointing", says former foreign minister Alexander Downer.
The current high commissioner in London, George Brandis, finishes his four-year posting on April 30 and is due to fly back to Australia on Saturday.
His replacement, to be appointed by the party that wins the May 21 federal election, would be unlikely to arrive in the UK to take up the position until mid-June at the earliest.
The Queen's Platinum Jubilee celebrations, marking 70 years on the throne, takes place across the UK on a four-day bank holiday weekend from June 2 to 5.
Mr Downer, Australia's longest serving foreign minister and a former high commissioner to the UK, has told Nine newspapers that Australia should have extended Brandis' term until his replacement could be appointed.
"I think it's a pity," Downer said.
"I'm surprised and disappointed that Australia won't have a high commissioner in London during the Queen's Platinum Jubilee celebrations."
Mr Downer said the British government would notice Australia's absence as it had "really invested in the relationship with Australia and Australia can't even be bothered to extend their high commissioner for two months for the Jubilee".
"It's not the end of the world, but it's very disappointing," he said.
British Conservative MP and co-chair of the Australian Parliamentary Friendship Group Andrew Rosindell said it was "a slap in the face".
"George Brandis has been an outstanding high commissioner and a fine representative of Australia. We're puzzled he's leaving at such an important time for our country," he said.
"Surely the high commissioner should have been invited to stay until the summer?
"As chairman of the group that works round the clock for better relations with Australia, this is a bit of a slap in the face for us to lose our high commissioner at this critical time," Nine newspapeers reported him saying.