Foreign Secretary David Cameron has taken his seat in the House of Lords after his official introduction ceremony.
The former prime minister will now be known as Lord Cameron of Chipping Norton, reflecting his long-held ties to the Cotswolds town in his former constituency, Witney.
He previously sat in the Commons for 15 years, including five years as leader of the opposition and six years as prime minister.
He was supported by Lord True, the Leader of the House of Lords, and Baroness Williams of Trafford, the chief whip in the Lords.
Lord Cameron, 57, wore the traditional scarlet robes for the short ceremony as he swore the oath of allegiance to the King.
The red benches of the upper chamber were more full than usual, with people also sitting on the stairs and on the step at the foot of the throne.
Those in attendance included Lord Pickles, who served in the Cameron Government.
Lord Cameron read the traditional oath: “I, David, Lord Cameron of Chipping Norton, do swear by Almighty God that I will be faithful and bear true allegiance to His Majesty King Charles, his heirs and successors, according to law, so help me God.”
Peers could be heard calling out to welcome him to the chamber as he arrived.
But Lord Cameron’s appointment to the upper chamber was not universally welcomed, with the Liberal Democrats writing to the Prime Minister’s ethics adviser urging him to launch an investigation into the new Foreign Secretary’s appointment.
Among her reasons for urging the investigation, Lib Dem chief whip Wendy Chamberlain cited Lord Cameron’s past lobbying work for investment firm Greensill Capital, for which he privately lobbied ministers in an attempt to win access to an emergency coronavirus loan scheme.
Ms Chamberlain said: “We need urgent clarity over David Cameron’s financial interests, which could lead to serious conflicts of interest while he represents the UK on the world stage.
“If he was serious about acting with integrity, Rishi Sunak would address these concerns by asking his ethics adviser to launch a full investigation into Cameron’s appointment.
“David Cameron has serious questions to answer over whether he can act impartially in the best interests of the British people. His judgment and integrity have all been questioned in recent years and for good reason.”
Meanwhile, the Lord Speaker on Monday used a speech at the London School of Economics to emphasise the importance of experience and independence in the House of Lords.
Lord McFall of Alcluith said ministers in the Lords often face a tougher grilling than those in the Commons.
He said: “Some suggest that ministers get an easy ride in the House of Lords. Let me tell you nothing could be further from the truth.
“One former minister who served in both Houses told me the experience of being questioned by peers is much more daunting.
“In the Lords, grillings are administered by former secretaries of state and leaders of the civil service, judges, ambassadors, European commissioners, ex-heads of bodies like Nato or the Joint Intelligence Committee.
“These are people who know their subjects intimately and can cut straight to the nub of any issue.”