In his younger years, Kevin Craig knew the inside of Wormwood Scrubs from visits to his uncle Donal, who was once described as a "reluctant" member of the IRA, jailed for helping the Brighton bombing planners.

Today, the London-born Craig, born to a Donegal father and Galway mother, runs PLMR, a highly successful public affairs and lobbying firm in Westminster, from a building owned by the Church of England just a few hundred yards away from the Houses of Parliament.

Twenty years ago, he could not get a security pass to work in the Commons for Labour MP, John Denham, even with a recommendation from former Conservative Party minister Earl Jellicoe.

“It would be different now because things have moved on,” says Craig, adding that Special Branch detectives “quite understandably” had raided the homes of his family and relations as they hunted for his uncle in the days after Brighton.

Fiercely proud of his London-Irish roots, Craig is equally proud of being British. “I can go downstairs in this building and I see where the House of Commons sat during the war [after its Westminster home was bombed] and I am proud of the British journey.

“It’s about time to ensure that those of a British/Irish heritage – like me – are more welcomed and accepted back in Ireland. When we go back, we want to feel welcome in what we feel is our country, irrespective of the British accent.

“The heritage of the diaspora in the UK is not yet regarded in the same light as that of the American-Irish. Why is that? Hopefully one day this will change. The sacrifices of my parents have given me every opportunity that I have ever had.”

Today, his father, Seamus, has retired back to Ardara, Co Donegal, to sheltered housing in St Shanaghan House. "If Carlsberg did sheltered housing, it would be St Shanaghan's," Craig says. His mother, Phyllis, who began life in London as a dinner lady, died in 2012.

After seven years, PLMR now has 30 staff and is turning over in excess of £2 million a year working with clients including the British Horse Society, Arthritis Research UK and lobbying on behalf of the Bingo Association.

It also represents veterans’ charity Combat Stress, which works with those who have suffered from post-traumatic stress disorder. “We do a huge amount of work helping them with PR and public affairs.

“The company is doing great stuff. As well as making money, the journey part is quite important, too. We have always given 5 per cent of profits to charity. It used to be very easy to be that charitable in the first years. Now, because we’ll do turnover this year of £2.5 million, a 5 per cent cheque is harder to write, but a better cheque to write.”

Unlike some lobbying firms, PLMR lists all its clients publicly. “We are unbelievably transparent. Other firms take a different approach. Other firms who don’t want that transparency won’t work with us. If we lose work, so what? We had an opportunity once to work with a Middle Eastern body, which we put to a vote of the management team here. They didn’t want to do it. Lobbying has got a bad old name,” he says, though he insists progress such as the introduction of the smoking ban in Ireland would never have happened without lobbying firms.

Five years ago, he became embroiled in an international controversy after Swedish animal rights campaigners accused him – during a meeting that was recorded by both sides – of trying to bribe them with a holiday to Australia.

Then working for the Australian Sheep and Wool Industry, Craig was fending off allegations of cruelty about the practice of removing strips of wool-bearing skin around a sheep’s buttocks. “It heals so they can never get infested by flies and die a horrible death. If they didn’t do it, more sheep would die, so it is done for the sheep’s welfare,” says Craig, still annoyed by the charges.

“That became in Sweden a ‘lobbyist attempts to bribe campaigners with foreign holiday’ story, which, obviously, since I recorded it, it wasn’t. It was big news in Australia for a bit. I said if I had had the means, I would have sued them.”

Craig previously worked for five years with major international law firm DLA Piper.

Today, Craig, the father of daughters Nuala and Tully, still regularly puts in 14-hour days. “It is very intensive, very hard hours. The causes have to be worth it. If you didn’t think that, why would you bother?”