Joe Walsh has the farmers. Noel Dempsey has the teachers. Michael Martin has the nurses.

Seamus Brennan, after almost a year in Government, has. . . deep breath. . . the taxi men, the bus drivers, the railway workers, the airlines, airport staff, coach drivers, Michael O'Leary and, of course, more than one million commuters.

It is a full brief and Mr Brennan appears to be relishing it. With about 20 years' experience in Government, he does not worry about offending people anymore. It is time to crack some eggs.

He wants to get things done, to leave an historic footprint and, as the traffic stacks up outside the window of his Kildare Street office, he knows this is the place to do it.

The next few months will be crucial. His ambitious plans have found favour with commuters, but have deeply troubled Aer Rianta and CIÉ management.

The cigar and brandy story ultimately did him little damage and a one-day stoppage by Dublin Bus and DART drivers also failed to halt his progress. So far, so good, but bigger tests lie ahead.

The press has eagerly trumpeted every announcement and written glowingly about Mr Brennan's vision for a joined-up transport system, but the media, like the public, will be watching to see if he can deliver.

Mr Brennan accepts this. Asked about his plans for Aer Rianta, CIÉ and Dublin transport in general, he simply says: "It is decision time."

There is no shortage of people hoping he will fail and there is loose talk around Kildare Street of people trying to drive a wedge between him and the Taoiseach.

However, he has received complete backing and, as long as that remains the case, it is hard to see what Mr Brennan's enemies can do to halt his plans to open up air, bus and rail travel to greater levels of competition.

"I am not naïve about the task ahead. I pushed through the penalty points system and it is now law. We have come a long way already. We have explained what we are doing ad nauseam and it is now decision time. I am absolutely determined on this. There may be a summer of discontent but I am pressing ahead with our plans, as down in the Programme for Government," he says.

Those plans are simple. A common thread runs through all of them - competition. Mr Brennan says he despises monopolies of any kind, private or public, and that is why he can no longer stand over the situation at Dublin Airport or at CIÉ.

In his Department and among the public, there appear to be two schools of thought. Put crudely, one broadly supports leaving Aer Rianta and CIÉ as they are, while the other favours privatising as much of the system as possible. Mr Brennan says he is somewhere in the middle.

He says Aer Rianta is first in the queue to be tackled. He wants a private terminal at Dublin Airport and says by the end of April he intends to go to Cabinet with his proposals. He says the recent report by former civil servant Mr Paddy Mullarkey makes the case, albeit with some qualifications, for a new terminal.

"I believe it will grow the market and bring in new airlines. We are going ahead. It will provide choice and give power back to the airlines. Already it has created a culture of competition at the airport."

Asked about job losses if Aer Lingus or Ryanair move their business to the new terminal, Mr Brennan is unmoved. He says a new terminal would grow the market, create new jobs, bring in new airlines and provide new routes.

The proposals he intends to bring to Cabinet will also include plans to break up Aer Rianta into three separate State-owned companies. Aer Rianta hoped Mr Brennan might go for a compromise option of retaining a central Aer Rianta board but letting three sub-boards run Dublin, Cork and Shannon.

But Mr Brennan says he wants the three companies to be entirely separate.

"We need to get them competing against each other. We need to put new people on those boards, people with international experience who can help them to grow the market further. I want the airport companies to compete with each other. For too many years, Cork and Shannon have been held back from fulfilling their potential. There is lots of untapped potential there," he says.

"If you look at the statistics I think you will find that thousands of people travel from Munster and the west to Dublin to take flights to Spain. Surely it's time to give them full services at Cork and Shannon."

He says the two regional airports can make money and, by attracting new airlines and taking some of the business which goes through Dublin at present, they can become profitable.

All of this will come as bad news for Aer Rianta chairman Mr Noel Hanlon, who opposes such plans. But Mr Brennan is slightly more conciliatory on the issue of Pier D, which Aer Rianta desperately wants to build.

"Aer Rianta are fully entitled to provide extra capacity at the airport. But Pier D is not a second terminal. I have written to them asking them not to enter into any contractual arrangements at this stage. There are concerns about the site they might want to use for Pier D. We have to make sure it doesn't end up squeezing out one of the sites for the second terminal. We have to make sure they do not end up sharing the same footprint. Otherwise I don't have a problem with Pier D," he says.

Getting change at CIÉ may prove even more difficult. Mr Brennan has tangled with some of the CIÉ companies before and, according to many, lost out badly. But not this time, he claims.

He is committed to opening up the market in rail, freight and bus. The first battle will be fought with Dublin Bus.

"I am in favour of franchising out the routes. We will need to put a regulator in place. I will dissolve the main CIÉ company. It will happen this year. Legislation will be needed. I have gone to the board meetings and they know where I stand. I support franchising because it will prevent two bus companies serving the same route. A condition of the licence will be that every few years it will have to be renewed. If there have been lots of complaints about a certain operator, well they will not get the licence the next time around."

These plans are likely to raise the hackles of unions at CIÉ, which fear that private operators such as Aircoach will simply cherry pick the lucrative routes and leave Dublin Bus in a mess.

Some of the unions had been pinning their hopes on semantics, that Mr Brennan was only committed to franchising out "up to 25 per cent" of the routes - i.e. it could be as little as 5 per cent. Not so, says Mr Brennan.

"I want to franchise 25 per cent of the routes, not up to 25 per cent of the routes. I haven't said anything about the others yet. I am not privatising any company. I am trying to bring competition into the market. I am engaged in talks but change is inevitable, whether it comes from the Supreme Court, the EU Commission or me."