Former Howard government minister Alexander Downer has been appointed the next high commissioner to the United Kingdom.

Mr Downer will replace former South Australian Labor premier Mike Rann, who will take up a new post as the ambassador to Italy.

Senior Foreign Affairs Department official and former government advisor Stephen Brady has been named Australia's new ambassador to France.

Foreign Minister Julie Bishop described Mr Downer as Australia's longest serving foreign minister with a long and distinguished political career.

He is following in the footsteps of his father, Alec Downer, who was also a cabinet minister and UK high commissioner.

Mr Downer's appointment comes after widespread speculation of a diplomatic reshuffle in February.

At the time, Labor described the tipped appointment as a "blatantly political move".

The Opposition said the Government should follow Labor's example in allowing Liberal appointees to complete their term in plum postings that they inherited while in Government.

Today's announcement follows Ms Bishop's decision to dump former Labor premier Steve Bracks from the consul-general post in New York in September.

Nick Minchin, a former Howard government minister, was appointed to the post in February, five months after Mr Bracks's sacking.