Spartan rail regulator Tom Winsor - who has just launched a new three-year plan for rail regulation - is a 'no-frills' Scot whose tough-talking appro ach fits perfectly with the public's demand to crack down on Railtrack.The man responsible for keeping the trains in check has experienced life on both sides of the legal tracks.

His earliest experience as a lawyer was in Dundee, where he worked in the Sheriff courts as a litigator, but by the time he was appointed regulator by deputy prime minister John Prescott in 1999, he was a partner in the top energy department of City law firm Denton Wilde Sapte (DWS).Along the way he went through the safe middle ground of top Edinburgh corporate practice Dundas & Wilson, and City firm Norton Rose, where he established a strong oil and gas energy expertise.After working on electricity privatisation in Northern Ireland for Dentons, he was seconded to work with the former rail regulator, John Swift QC, from 1993 to 1995.

This gave him a strong input into the framework of rail regulation which he is now responsible for enforcing.He worked hard - 'I moved a bed into the office, and I used it often,' he says - but adds that these were the 'most challenging, interesting and rewarding two years of my legal career'.He then returned to DWS to establish what he calls 'the strongest rail regulatory practice in the the City' with Christopher McGee-Osborne.Mr Winsor attracted big names in the sector such as GNER and Virgin.

But while acting for the private companies, Mr Winsor says he became 'increasingly frustrated by the inaction' of the Office of the Rail Regulator.

'It was not using its powers proportionately or fairly,' he says, adding: 'The regulator failed to exercise his powers in a number of respects.'With the change of the political landscape in 1997, Mr Swift - a Tory appointee - 'may not have found himself flavour of the month', says Mr Winsor.By September of the following year, the post was advertised.Mr Winsor, a card-carrying Labour supporter, was interviewed and selected for the job by the deputy prime minister.DWS has a 12-month termination notice period for partners, but Mr Winsor came to an agreement with managing partner James Dallas that he would be allowed to go after three months, on condition that he passed his know-how on to colleagues before leaving.The job may not come with as much cash as a senior equity partnership at DWS - 'it's worth about half' says Mr Winsor of his publicly disclosed £170,000 salary - but the office itself, located in a 'heritage suite' of the Prudential's old Gothic headquarters in Holborn, is of ministerial proportions.

'Some people are motivated by more than just money,' Mr Winsor says.Within months of arriving in the job in 1998 he found himself in at the deep end first with the Paddington crash - in which 31 people were killed - and last year with the Hatfield disaster, in which four people died, and which, he says, 'led to the complete disintegration of the integrity of the rail system'.In an early coup in August 1999, Mr Winsor levied a £40 million fine against Railtrack to force it to raise standards.He has just launched his three-year plan, outlining a programme of 'maintained and increased vigilance and regulatory scrutiny in relation to railtrack's stewardship of the network'.

He has signalled that he will not let up with Railtrack: 'The company's performance last year, and the effects which that had, not only on its own prospects and standing, but on the positions of others, has justified that approach.'The plan is threefold: creating a strengthened network licence, which will hold Railtrack more tightly to account; reforming the financial framework to provide Rail track with incentives to grow its traffic; and creating stronger and simpler contracts between Railtrack and its train operator customers.Although Mr Winsor does not think his past as a lawyer makes him a better regulator, he says that, compared to other industries, the railway is 'legally intensive'.

His former rail practice means he 'knows where the bodies are buried', he adds.If the three-year plan is to be carried through by Mr Winsor, he will need to be in favour with the powers that be.

As a political appointee, he is clearly vulnerable to political upheaval, however unlikely that appears to be at the moment.Although he has always been 'fascinated by politics', and that at the beginning of his career he considered running for Parliament (for Labour), he says Parliament 'really is a greasy pole', and 'I am no politician'.He says that despite his membership of the party and descriptions of him as a Labour activist, he will meet with 'any member of Parliament or minister, including the prime minister,' but that politicians cannot give him orders.Mr Winsor has a tenure of five years as regulator, but says he does not know whether he wants to be reappointed.But what of the post-regulation world - does he have any idea where he is going next? 'I'll probably go back to being a partner in a City firm, or perhaps even the Bar, or maybe not a lawyer at all.

There will be other opportunities.'And as to whether he wants to go to the House of Lords perhaps in these days of public-spirited peers, he replies quickly: 'I can't live on only £34 per day with a family.' Public service has its limits, it seems.