He is litigious, and has launched legal proceedings against so many people that some people have wondered if he would have liked to have become a lawyer . . .

although even lawyers' earnings would not come close to his own.

Sean Dunne's plans for the development of the old Jury's Hotel site at Ballsbridge, Dublin, are the culmination of a career which is extraordinary even by the standards of property development in contemporary Ireland.

And the Jury's site, in its extravagance and scale might just prove his Taj Mahal. The deal, constructed in a blaze of publicity, could be a monument to Dunne's ambition, or a folie de grandeur. The plans include a 32-storey tower of apartments, four smaller towers of 11 storeys, two glass pyramids, an ice skating rink and a jazz club.

The cultural consultant on the project is Michael Colgan, of the Gate theatre. "The Jury's site is an important development for the whole industry, " said one commentator. "If Dunne runs in to trouble on it, that could be catastrophic. He paid a strong price for it. If he doesn't get the height he could be in trouble. This is mega stuff and everyone is watching very closely. This has taken over his life. Whatever the price of the site [about 270m] no one has that kind of money. He's very heavily geared [borrowed]. He has to hold the confidence of the banks and at the moment nothing is selling. The market has stopped."

From the Georgian splendour of his Merrion Square headquarters, which he has tastefully restored, and the domestic bliss of his home with his second wife, Gayle Killilea, in Shrewsbury Road . . . already the subject of two separate High Court cases . . . Sean Dunne is mobilising his considerable resources for the Jury's initiative. The planning application is not due until next March.

"Sean Dunne is very much a business man rather than a builder, " said one man.

"He watches every press release. He's a good letter-writer. He's a cufflinks and Armani suit kind of guy."

Sean Dunne owns two thirds of the proposed site. The adjoining sites belong to Jerry O'Reilly and David Courtney and to Ray Grehan of Glenkerrin Homes (who developed The Grange in Stillorgan and bought the old UCD Veterniary College site, on two acres, in Shelbourne Road). "So far there has been no real discussion between them. Sean seems reluctant. He's very headstrong, " said one man who admires him.

Asked to name one player Sean Dunne would respect, this man named Sean Mulryan of Ballymore Properties, with whom Dunne developed Charlesland in Greystones, getting massive lands rezoned to build 1,800 residential units and a science and technology park: "He doesn't take his competitors too seriously. He would respect Mulryan, but they're not close. Dunne ran that [rezoning] campaign too."

Dunne sold his half of the Whitewater shopping centre in Kildare to the accountant and property developer Kevin Warren, after another row. "Dunne still got a super price, " said one man admiringly. It is rumoured to have been 250m but, as one sceptic put it "everything I've ever heard about Sean Dunne is an exaggeration".

Last July, Dunne and his wife were on the front page of The Sunday Independent, beside a headline which talked about "a honey trap" conspiracy to destroy their marriage. It says a lot about our old stereotype of the Irish builder that people are surprised by Dunne's wit and by his charm.

Another person who has regular dealings with him said that meetings with Dunne felt more like job interviews. "You wouldn't be putting out any waffle, put it that way, " he said.

Socially, Dunne is competitive with other men, and famed for his arguments. He is willing to go on the attack over both real and perceived slights.

Unlike many rich men he is a spender, bringing friends to Munster matches in private aircraft; taking over the Unicorn restaurant for his annual Christmas party, announcing his second marriage whilst cruising on the Mediterranean on the Onassis yacht, Christina.

"A lot of those property guys wouldn't spend tuppence, " said one man who organised charity events. "Dunne's not like that. He's generous. I know that he's helped out a lot of people who were in trouble."

Although he can be found quietly enjoying a drink in Doheny & Nesbitt's pub on Baggot St in Dublin , it is for his rows that Dunne is best known.

"He's a control freak, " said one man.

"It's real 'you said this, I heard that', schoolkid stuff."

Dunne is a rugby fan, and was an enthusiastic player in his day. But rugby has brought him other pleasures. His first big deal when he returned from the UK, the Booterstown development, St Helen's Wood, was constructed with men he met in Lansdowne rugby club. Men such as Tony Garry of Davy Stockbrokers, and David Shubotham, the St Helen's Wood scheme was a success, even in a city as muted as Dublin was in the late 1980s and early '90s. It was quickly followed by a row with his business partners. St Helen's set Dunne up; he walked away with the funds to start serious investment. He bought a Rathfarnham farm from Guinness heir Garech de Brun (there was another legal controversy here). He developed St Raphael's Manor in Celbridge, Co Kildare, and Hollybrook, on Brighton Road in Foxrock. He built the Lagoon Beach resort in Cape Town, South Africa, with a fivestar hotel and 180 apartments, many of which were snapped up by Irish buyers.

He also built the Kildare home of our former Minister for Finance, Charlie McCreevy, now European Commissioner.

"He was great for mixing with politicians, " said another.

Indeed, Dunne met Gayle Killilea at the annual Fianna Fail outing, the Galway Races, in the lobby of the Radisson Hotel.

Dunne was already separated from his first wife, Jenny, originally an Aer Lingus air hostess. She is from Ashbourne, Co Meath, and the sister of businessman Raymond Coyle. "Jenny is a smashing person, " says one man.

Gayle Killilea is 20 years younger than Dunne, the mother of his third son, Bobby Luke and, it was revealed last week, expecting his fifth child. Even Dunne's enemies admit that the two seem happy together and note that Gayle Killilea has been seen bringing Dunne a packed lunch during his long days in court. He also took up the legal cudgels on her behalf, against The Sunday Independent, where she had once worked as a gossip columnist, although the case is thought to have been settled out of court. Gayle Killilea recently qualified for the Bar.

For her 30th birthday, Dunne hosted one of his fabulous parties in the Park Hotel in Kenmare, where guests were asked to follow a Pirates of the Caribbean dress code.

Dunne himself was dressed as an admiral and legend has it that one of his guests asked if he could park his comparatively small helicopter in a more discreet location, away from the larger whirlybirds, because in the testosterone-charged world of property barons . . . and as the ambitious plans for the Jurys site show . . . size matters.

C.V.

Profession: Property developer.

Chartered surveyor Born: Tullow, Co Carlow, 1955 Education: Patrician Brothers, Tullow, Vocational School, Tullow, Bolton Street College of Technology. BSc Trinity College in construction economics Married: Firstly to Jenny Coyle, one daughter, two sons. Secondly to Gayle Killilea, one son Hobbies: Rugby, getting his own way In the news because: Plans for his development of the Jury's Hotel site in Ballsbridge were revealed to Dublin City councillors last week