The legal eagle of the Senate, George Brandis, is on the cusp of giving his closing address.

The former Attorney-General is due to take up his new role as Australia's High Commissioner to the United Kingdom next month.

He replaces another political appointee, former foreign minister Alexander Downer.

The outgoing Queensland senator is expected to give his valedictory speech to the upper house on Wednesday after 17 years of service.

He told his colleagues at the coalition partyroom meeting on Tuesday he was grateful to close his political career in a satisfying way.

Senator Brandis said he may see some of the same faces in London when he becomes a diplomat.

"I will think of you fondly but not constantly," Senator Brandis said.

He told his colleagues when he entered parliament in 2000 people had written off the Howard government but with good leadership, judgment and a united partyroom they went on to win the next two elections.

Senator Brandis expressed his confidence that that can be done again if the Turnbull government is unified and focused.

Senator Brandis's move to London was among the worst-kept secrets in Canberra in recent years.

The move to the UK is not uncharted territory for the senator, who studied at Oxford in the 1980s alongside former prime minister Tony Abbott.

A LOOK BACK AT GEORGE BRANDIS' TIME IN POLITICS:

* Brandis was lauded for his takedown of One Nation leader Pauline Hanson when she controversially wore a burka into the Senate.

"To ridicule (the Muslim) community, to drive it into a corner, to mock its religious garments is an appalling thing to do and I would ask you to reflect on what you have done."

* Brandis's speech on the same-sex marriage bill also won high praise.

"You are not unusual. You are not abnormal. You are just you. There is nothing to be embarrassed about. There is nothing to be ashamed of. There is nothing to hide. You are a normal person and, like every other normal person, you have a need to love. How you love is how God made you. Whom you love is for you to decide and others to respect."

* In 2014 he defended people's rights to be bigots.

* Brandis once struggled to explain what metadata was during a car-crash interview on Sky News. "The web address, um, is part of the metadata."

* Taxpayers chipped in for a $15,442 custom-made bookshelf for Brandis in 2014, after his first $7000 one wouldn't fit in his new office.