David Cameron appeared to take a sly dig at fellow former prime minister Boris Johnson in his first speech in the House of Lords.

Lord Cameron of Chipping Norton said he had been no “Cincinnatus hovering over my plough”, in reference to Mr Johnson’s final words as he left office.

Mr Johnson had likened himself to Cincinnatus, who left ancient Rome to work on a farm only to be called back to save it from crisis, with many interpreting Mr Johnson’s words as him hinting at a future return to frontline politics.

I have not been sitting like some latter-day de Gaulle at Colombey-les-Deux-Eglises waiting to be asked

The new Foreign Secretary told peers he had been “surprised” to be asked to return to Government, and had not been “sitting like some latter-day de Gaulle at Colombey-les-Deux-Eglises waiting to be asked”.

He joked that the ornate surroundings of the upper chamber are a “significant upgrade” from his “now-infamous shepherd’s hut”.

Lord Cameron cannot address the House of Commons because he is not an elected MP, which critics argue will reduce democratic accountability.

Instead, Foreign Office minister Andrew Mitchell will deputise for him in the Commons, while he will answer questions from peers monthly.

However, the Foreign Secretary told peers he is “happy to consider other appropriate mechanisms so that Parliament is able to scrutinise all the work of my department”.

Lord Cameron was speaking as he opened the debate for the Trade (Comprehensive and Progressive Agreement for Trans-Pacific Partnership) Bill’s second reading in the upper chamber.

He said: “It is truly an honour to stand here at this despatch box and make my maiden speech in this House. I have always respected the work that is done here, so often a patient, diligent and considered complement to the other place.

“And I hope to play a full part in your Lordships’ House.”

He added: “When I look at the ornate, carved wooden panels that surround us and compare them to my now-infamous shepherd’s hut, I can tell you this is already a significant upgrade.”

The Foreign Secretary said that wanting to serve under Rishi Sunak, whom he described as a “strong and capable Prime Minister”, was “one of the reasons why I accepted his offer of this role”.

He said: “I hope that some of my experience will help the Prime Minister in meeting the vital challenges that we face as a country.

“That said, it was a surprise to be asked. I have not been sitting like some latter-day de Gaulle at Colombey-les-Deux-Eglises waiting to be asked, how shall I put it, to take back control.

“Nor am I Cincinnatus hovering over my plough. I leave all classical allusions, and indeed illusions for that matter, to another former prime minister with whom I shared a number of educational experiences.”

Lord Cameron also joked that he was in the “delicate position” of many of his fellow peers being there at his own nomination, and joked that the Liberal Democrat benches are “particularly full” due to their time in Government during the coalition years.

Lord Cameron said: “I am in what Margaret Thatcher described in her maiden speech here as in a delicate position, responsible for proposing to elevation to this House quite so many of its current members.

“So I hope you will forgive me for my part in putting – how can I put it – space here at a premium.

“I note that the Liberal Democrat benches are particularly full. I always said to my deputy prime minister and partner and friend Nick Clegg that his party would feel the benefit of participating in the coalition for many, many years to come.

“I just didn’t predict exactly how that would manifest itself.”

He emphasised that he is not the first peer to sit in the Cabinet, with Lord Mandelson, Lord Adonis, Lord Frost and Baroness Morgan of Cotes also doing so in recent times.

Lord Cameron said: “Lord Mandelson sent me a particularly charming welcome, but he pointed out that I am a comeback novice and this is only my first one, compared with his three.

“I suppose my response should be that to make three comebacks you need both his prodigious talent and you need to be sacked twice by the Prime Minister, which is a fate I’m hoping to avoid.”

Former Chancellor of the Exchequer Lord Lamont of Lerwick welcomed his former special adviser to the upper chamber, saying: “It’s a mystery to me why we have today still this self-defeating idea that former prime ministers should never return to frontline politics and I’m glad Lord Cameron has broken that rule.”

He added that he was not surprised by the appointment, as Lord Cameron “wasn’t wholly convincing in his denial that he wasn’t remotely interested” in a conversation they had a year ago.

Lord Cameron used his speech to lay before peers the benefits of joining the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), a trading bloc made up of 11 countries: Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.

He added that the Bill, which provides measures to ensure the UK will be compliant with international obligations when it accedes to the CPTPP, is “narrow” but with “considerable” benefits.

He concluded: “It is an investment in a brighter future – and I should know, because I was the future once.”