Do you know this man?

Carillion's combative chief executive John McDonough does not do interviews for the sake of it. In fact, since taking the reins at the £2bn-turnover contractor more than two years ago, this chat is the first he's granted to the press. "It's not that I deliberately avoid a high profile," he says with a hint of his Wigan hometown in his accent. "It's just that there's so much going on in the company that time's limited – I've only agreed to do this interview as it'll benefit the company profile."

McDonough took over as chief executive from the far-more-public Sir Neville Simms. He knew comparisons with his predecessor would follow. "I have a great working relationship with Neville – but don't get me wrong, he doesn't interfere." On the contrary, he says Simms, now chairman, has been a great source of guidance.

Since his arrival, McDonough has set about implementing a huge modernisation programme. He has begun trimming the executive board, scaling back Carillion's contracting arm and refocusing the company on the services sector. The aim is to create the ideal outfit to undertake long-term PFI contracts. "Under Neville, Carillion was like a huge big tanker – it was heading in the right direction, but it was slow," he says. "What I've tried to do is turn the operation into a streamlined speedboat."

Executives at Carillion say McDonough is a tough man who does not suffer fools gladly. One senior manager says: "He's straight-talking – and inclined to swear in order to drive home a point." And it is while discussing the services sector and the PFI that the first glimpse of the more abrasive side of McDonough's personality emerges from the corporate front.

He is particularly angry at the monstering the PFI has received from the press. "Just because companies in the services sector working on PFI contracts are not doing too well, the PFI process should not get the blame – that's just bollocks," he says.

Not that it is the press alone who are to blame for the PFI's somewhat muddy reputation; the City, too, is guilty of a lack of discrimination. "The market gets jittery and it affects everyone," he says. "If there's a story in the press about how badly a particular company is doing, and they do PFI work, it becomes a PFI story. That's what's wrong – it should be about how that company is handling the PFI process."

He asserts that Carillion has had nothing but positive dealings with the PFI: in 16 projects across the health, transport and defence sectors, not one has been delayed by so much as a day.

Under Neville, Carillion was like a huge big tanker. What I’ve tried to do is turn the operation into a streamlined speedboat

But it is not just the PFI that McDonough feels strongly about. He is also keen to put Carillion in the running for any contracts that may be available to rebuild Iraq. He says that he would take a "close look at any opportunities that may arise" in the region.

But McDonough tempers this with a concern for his workforce. "Wherever we work in the world we carry out a 'country sign-off' that is led by me, and basically involves a risk evaluation of working in that country," he says. "If we do pitch for the rebuilding contracts then Iraq would have to undergo one of these reviews." He adds that the safety of the workforce would be the firm's first concern.

An intensely private man, McDonough backs away from questions about his career history and personal life. But he does reveal that he studied mechanical engineering at Imperial College London, spent most of his working life at the giant US services firm Johnson Controls, reaching the rank of vice president, and that he has lived in Germany for five years and Singapore for three. That is as revelatory as he gets.

Fifty-one-year-old McDonough admits that he has had limited experience of the building sector, but he says has tried to turn that to his advantage. His manufacturing and services background, he says, have taught him the importance of continuous improvement, brand identity and customer service. "One of the key cultural changes I wanted was to have the Carillion company operating from a single point of contact that customers can learn to know and trust."

McDonough is looking to implant his continuous improvement philosophy into Carillion. He is seeking also to add one or two bolt-on companies in the services sector to complement the acquisition of the facilities management arm of Citex late last year. And he is keen to solve staffing problems: "The labour shortages are very severe in this sector and I'm very aware of it," he says.

Carillion is recruiting English-speaking engineers from abroad to fill the skills void and to cope with huge infrastructure maintenance contracts, such as the West Coast Main Line. McDonough says the firm recruited 50 South African rail engineers recently. But he says that that was only a tactic; his strategy is to develop the skills of existing personnel.