Nigel Dodds, the Democratic Unionist Party leader at Westminster, is reflecting drolly on his party’s recent popularity: ‘I certainly think that the last year or two has been remarkable in the number of new friends we have encountered, people who are very keen to have a cup of tea or chat to you or whatever. I don’t put it all down to our natural charm.’ As pre-election talk of political pacts thickens — with both Conservatives and Labour angling for support — former House of Commons wallflowers have found their dance cards increasingly full.

Which of the main parties might feel like a more natural ally? I ask. Dodds won’t commit to either, but observes that historically unionists lean towards the Tories: ‘Growing up, I think naturally we felt the Conservatives were more trustworthy on the Union.’ On the other hand, ‘The DUP had reasonably good relations with the Labour government in terms of Gordon Brown and working through the St Andrew’s Agreement. So we are not in the pocket of either of the main parties.’

The 56-year-old Dodds — an Orange Order member with a First in law from Cambridge — has been a player in Northern Ireland politics for decades now: at 29, he was the youngest ever Lord Mayor of Belfast. Yet after youthful academic success in the tranquil halls of St John’s College, Cambridge, didn’t he consider a legal career in England? ‘I was tempted. But I never really seriously considered it because I’m a political animal and if you have politics in your blood — and especially Northern Ireland politics — it just basically drives you.’ Nonetheless, he says, his mother, a former school dinner lady, might have liked him to have been a solicitor: something prosperous, quiet and solid.

Instead, drama has never been far from Dodds’ life amid the acrimony and adrenalin of Northern Ireland politics. He grew up in Enniskillen, Fermanagh, and was in his teens in the early 1970s when the Troubles flared up in earnest. His family attended the Free Presbyterian church, in an era when the thunderous rhetoric of its leader Ian Paisley — heavily laced with exhortations against the Catholic Church — was first making inflammatory headlines. At the same time the IRA was waging a sectarian border campaign in Fermanagh as it sought violently to purge the area of local Protestants and their families. The IRA’s targets were frequently serving or former members of the British Army’s Ulster Defence Regiment: Dodds’s own father Joe, a DUP councillor, was in the UDR.

A 1972 double IRA shooting, of the Protestant farmer and UDR man Tom Bullock and his wife Emily, made a deep impression on the young Dodds: ‘I remember going to stand outside the hospital after the Bullock family were murdered on their farm, and there was such an outpouring of grief that people gathered to see their coffins being brought out of the hospital.’ In that atmosphere, ‘Here was Ian Paisley speaking up at that time when you didn’t really know what the Ulster Unionists were about. Jim Molyneaux was in charge of the UUP, doing stuff in Westminster, and it didn’t really seem relevant to what was happening on the ground.’ Yet at the time, he says, ‘the DUP was seen as almost a fringe cult movement’ while the bulk of unionists gravitated towards the more moderate, middle-class Ulster Unionist party. After the 2010 election, the Ulster Unionists did not have a single Westminster MP.

I put it to Dodds that the DUP has often been viewed from outside as a sectarian party, particularly by Catholics: has there been a shift? ‘Yes I think there has been,’ he says, while arguing that people are quick to label unionists sectarian simply for being unionist, yet not applying that label to nationalists and republicans. Still, he says that the DUP has broadened from the days when it was seen as ‘very much a one-man band’, that man being Paisley senior. Under its new leader, Peter Robinson, the DUP appears keen to move away from the divisive theological language that was once Big Ian’s stock-in-trade, and on to more straightforwardly political terrain.

‘Peter has made the point that he wants to reach out and make the Union something that Roman Catholic people feel comfortable about,’ he says. ‘We have a long way to go. We’re not dealing with years here, we’re dealing with decades.’ He is nonetheless vocal on the importance of flying the Union Flag at Belfast City Hall: ‘It speaks to our British identity.’ Yet, he says, many ordinary Catholics share the social conservatism of the DUP — opposition to policies such as gay marriage and easily accessible abortion — and tell him while canvassing that on those particular issues, ‘I don’t have anybody in my community who represents me any more.’ Over the years he has visited the families of murdered loyalists, IRA victims, and Catholics murdered by loyalist paramilitaries: ‘I went to make the point that all human life is sacred no matter what people believe or anything else. These deaths are tragic and terrible for the families.’

One of the more shocking incidents of the Troubles came in 1996, when IRA gunmen made an assassination attempt on Dodds and his police bodyguards in the children’s ward of a Belfast hospital, as he and his wife Diane visited their seriously ill seven-year-old son Andrew. One policeman was injured in the attack. Andrew, who suffered from spina bifida and hydrocephalus, died two years later. I ask Dodds how it felt when the DUP first shared power with Sinn Fein politicians at Stormont in 2007 (a move which triggered the striking sight of Ian Paisley and Martin McGuinness regularly roaring with laughter together, leading Ulster wags to dub them the Chuckle Brothers).

Dodds is less effusive. ‘It’s very, very difficult personally,’ he says. ‘It never leaves you, something like that. I’ll never be a friend or be chummy with these people, but I’ll do business with people who are political opponents in the best interests of Northern Ireland, including those of victims.’ Does he follow Gerry Adams on Twitter? (The Sinn Fein president has become notable for tweeting about rubber ducks and teddy bears, and recently told an interviewer that he trampolines naked with his dog.) ‘I don’t, but I know people who do and tell me about his strange, bizarre and esoteric tweets.’

With the revelation that the SNP would seek to bring down a minority Conservative government, the Tory party’s options are narrowing in the event of a hung parliament: the DUP Westminster MPs — there were eight of them last time — could prove crucial to its grip on power. Yet although the SNP and the DUP have radically different visions for the future of the UK, there are strong cultural similarities: politicians in both parties instinctively understand the vigorous cultivation of local contacts, the importance of a strong handshake and a timely family inquiry, the ritual sharing of tea and a tray-bake and the banishment of condescension. Dodds points out the dangers of overstyling one’s image, referring to the fallout from Miliband and Cameron’s recent interviews in their kitchens: ‘If you’re going to do a political interview, just do it in your workplace.’

He continues: ‘Even though the Scots Nats believe what they do, there is quite a good personal relationship between them and the DUP. Ian Paisley and Alex Salmond got on famously.’ But a Miliband alliance with the Scots Nats would be ‘the worst thing you can imagine for the United Kingdom’.

Last month Dodds set forth DUP demands in exchange for support: a UK-wide scrapping of the ‘harsh’ bedroom tax; an in-out EU referendum; and guarantees on defence spending and border controls. He firmly believes in a muscular Britain that plays ‘a role upon a world stage’. Yet his party colleague Ian Paisley Junior later chipped in with a blunter hard-cash demand of ‘hundreds of millions’ in extra UK money for Northern Ireland. Is the price going up? ‘No. We are unionists but it’s not just about Northern Ireland, there are issues in terms of the good of the UK that we are passionate about.’

What, then, would be the ideal outcome of the election? ‘As Peter Robinson said, we are easy about which party comes out on top — provided it comes out needing the support of just about nine or ten MPs.’ At that prospect, Mr Dodds permits himself a small, wry smile.