Entering the livingroom of Lord and Lady Trimble in Lisburn, you are confronted with what seems like a caricature of what you'd expect the former first minister and Ulster Unionist Party leader to be doing in his retirement from frontline Northern Ireland politics.

On the radio, BBC Radio 3 is playing classical music. There is an open copy of the Spectator magazine beside him and on a little table, a book by Roger Scruton about probably his favourite composer, The Ring of Truth: The Wisdom of Wagner's Ring of the Nibelung.

This is David Trimble in high Tory relaxation mode. He and Daphne spent 10 weeks this summer during the Brexit referendum drama on a narrow boat – rather like a small barge – cruising along England's canals.

He has safety advice for anyone unfortunate enough to fall into a canal: “If you are on a boat and you fall in then the first thing that you must do is to stand up.”

He is delighted with the vote to quit Europe – "the European Union economically is a failure" – but more of that shortly. He also is quite happy to offer his opinion on a range of politicians such as David Cameron, Boris Johnson, Enda Kenny, Micheál Martin, Peter Robinson, and, of course, Gerry Adams.

He is as antipathetic as ever to the Sinn Féin president, even if his anecdotes about Adams veer more to the humorous than the venomous.

With deadpan astonishment he recounts how US senator George Mitchell chaired more crisis meetings at Winfield House in London in late 1999.

The plan was to have the key adversaries up close and personal to try to bring a degree of humanity to proceedings. Which was how, with Mitchell in the middle, Trimble and his UUP colleague, Sir Reg Empey, were in direct talks with Adams and Martin McGuinness.

“I remember on one occasion when Gerry started saying, ‘Oh we ought to get to know each other better’. He elaborated on that, and he said, ‘we should dine together, go out together’. And he got to the stage where we should go on holiday together.”

And as one conjures a picture of Adams and Trimble on that narrow boat chugging along some English canal Trimble adds, “At that point I leaned forward to look past Gerry and caught Martin’s eye and said, ‘You know Martin, just because you get to know someone better doesn’t mean you get to like them any more’. That put an end to that.”

Missing M&Ms

Daphne Trimble then comes in with the story of the M&M sweets. “Oh, yes, that was before Winfield House,” Trimble remembers.

His wife explains that, shortly before Trimble and John Hume were to receive the Nobel Peace Prize in Oslo in December 1998, the Trimbles were invited to an event at the US National Press Club in Washington which the Sinn Féin president also attended.

The four Trimble children were also there, including a then 10-year-old Nicholas, now a UUP councillor. The press people had laid on treats for the children, explains Lady Trimble.

“Nicholas had gathered up a little supply of M&Ms, and set them at his table. But he then got up to get himself a drink, and came back to find Gerry Adams had pinched his M&Ms.”

Trimble spends most of the working week on Conservative House of Lords business in London and returns home at the weekends. But he keeps an eye on Irish and international politics.

“Enda has done a good job and Micheál Martin has been very clear in his approach to Sinn Féin,” he says.

In the Republic “it’s good to see economic resurgence”, he adds.

His view remains jaundiced on former DUP leader and first minister Peter Robinson who, he says, just can’t admit that the UUP and the SDLP took the big risks to ensure the powersharing Northern Executive, notwithstanding all its tribulations, would actually function and survive.

“The DUP and Sinn Féin are operating within structures that we and the SDLP created. They may go around saying what great chaps they are but they are actually living in the world that we built,” he says.

“One of the amusing things about the DUP and Sinn Féin, and it is part of the reason for their problems, is that neither of those two parties can give an honest account of how they got to where they are now.”

And: “Peter, at the end of the day what did he actually ever do?”

Managed to keep Stormont working perhaps? “He was a good campaign organiser but not terribly good in leadership,” is as much as he will offer in response.

And as for the current First Minister Arlene Foster who, as an Ulster Unionist, gave Trimble considerable grief, before jumping to the DUP? "We will wait and see."

The UUP and SDLP are now the official opposition at Stormont and therefore don’t have any Ministers in the Executive. Trimble sees hope for the two parties that were in command when the Belfast Agreement was struck in 1998 but are now very much subordinate to the DUP and Sinn Féin.

“I think it is significant that they have decided to work in opposition. It has not been worked out yet but I think the logic of the situation is that come the next Assembly election there has to be a degree of co-operation there,” he says.

Impending crash

He believes the “shine is coming off Sinn Féin” and that there are opportunities for the SDLP. “It may be that there is a market for an alternative. On the other hand it may take longer for the electorate to get their minds around the situation. But I do think inevitably that is the way things should go.”

His former UUP party adopted a lukewarm Remain stance in the EU yes-or-no referendum but Trimble was a firm Leaver. He says not only is the EU an economic failure but that with the euro – notwithstanding its strength against sterling – there is a “big crash waiting to happen”.

“The EU keeps wanting to damage our biggest industry, which is financial services. There is no economic argument for being in Europe.”

He is dismissive of the “dark mutterings” of the EU imposing tariffs on UK goods when Brexit is completed. How could Brussels adopt such a policy when “they sell to the UK some £80 billion of goods more than we sell to the EU”?

And he has no concerns about a hard Border or a deterioration in North-South relations or huge influxes of immigrants or terrorists exploiting Irish ports to gain access to Northern Ireland and then to Britain.

“An awful lot of nonsense was said about that. We operated from nineteen-twenty-something until 1972 with different tariffs North and South without causing the collapse of the political process. And with regard to continuation of the Common Travel Area, my impression is that very positive discussions are going on with the various authorities to see ways in which we co-operate so that we can still keep eyes on who is passing through without having to have big elaborate machinery on the Border. So that’s okay.”

Trimble says Europe was determined not to give David Cameron a sellable deal. “Cameron was very capable, very pleasant, charming. But I am not sure just what stock of political commitment he had, what his basic outlook was, what was it he was trying to achieve. It was not altogether clear.”

Boris for PM

He thinks Theresa May is doing a good job. He has regard for Boris Johnson, who he suspects may yet end up as British prime minister regardless of the “tragicomedy” of his failure to succeed Cameron. “Boris surrounded himself with strong and capable people and then delegated. Cameron on the other hand surrounded himself with his chums who weren’t in the same league. It was something he was told about again and again and again, but he preferred to keep the comfortable environment that he had. Boris is very capable.”

Aside from his House of Lords duties, Trimble is collaborating with his former chief of staff in the UUP, David Campbell, to write a new book on the peace process.

That was triggered by reminiscences he delivered last year to a group of American students at an event organised by the father and son historians, Paul and John Bew. Trimble recounts how his penchant for walking out of meetings prematurely – whether red-faced and angry from a television studio, or due to other engagements – had preceded him.

He told how in the late 1990s he met US president Bill Clinton and Gerry Adams in Washington. At the time, a big marquee event was happening on the lawn of the White House. The meeting overran but again Trimble felt he had to leave because he and Daphne had a restaurant booking – “I was not going to miss my dinner”.

But this time he had briefed his hosts, with the result that in order to avoid headlines about another “Trimble Walkout”, Clinton had arranged it so that one of his most senior advisers walked with them through the crowd declaring, “He has a very important engagement, he is not walking out . . . He has a very important engagement, he is not walking out . . . He has . . .”

The Bews told Trimble they weren’t familiar with this yarn with the result that Trimble and Campbell – largely based on Trimble’s papers and detailed diaries that Campbell kept – decided that perhaps there were other stories about the process to be told. The dastardly tale of the purloined M&Ms also should be contained therein.