Mawhinney, one of the Cabinet's new boys and one of the Prime Minister's closest allies, is renowned throughout Whitehall for his no-nonsense approach and his refusal to take any flannel. 'It is not', according to one friend, 'that he is cross or brutal, but he knows that many of our ministers have been led by the nose by civil servants.'
Last Monday (his 54th birthday) Mawhinney gave an interview to his local newspaper, the Peterborough Evening Telegraph, during which, true to form, he marched to the phone, dialled the departmental hotline and 'bawled out' a civil servant.
His new officials must feel in the firing line; not only is Transport at the heart of a crippling rail strike but also on the receiving end of last week's European rebuff to the British case against state subsidies to Air France.
At his last job as Minister of State at the Department of Health, Mawhinney played 'hard cop' to Virginia Bottomley's 'soft cop', confirming his political tag as a man of the 'hard centre'. Little wonder that pundits predicted a high noon with the signalmen.
His first days in the job, however, proved that the image of the macho politician represents only part of the truth. Mawhinney ended weeks of pretence that the Government has little impact on the dispute and intervened openly in an attempt to get the parties into discussion. A statement from the new minister argued that the deal on the table was worth more than the 5.7 per cent offer withdrawn after a Government veto. Before it went to Number 10 for approval, Mawhinney's draft made explicit that it was actually worth 7.2 per cent. He believes, according to one minister, in 'softly, softly catchee monkey'.
Mawhinney, whose father was a Belfast restaurateur, was born in 1940 and educated at the Royal Belfast Academical Institution. 'Inst', as it is known, is a robust day school for boys and one of three or four seats of learning that groom the Protestant establishment of Northern Ireland. His career path was academic science; he attended Queen's University in Belfast, studied radiation biology at the University of Michigan in the United States and went on to the University of London. Spells as an assistant professor of radiation research in Iowa, then a lecturer in London, have left their mark. According to one colleague he 'works with a very scientific method. He takes a proposition, examines the evidence and then comes to a conclusion'.
America left a big impression. It was, according to one version, John Kennedy's presidential victory that first interested Mawhinney in politics. Moreover his wife, Betty, is American (they have two sons and a daughter) and he lists Anglo-American relations among his interests.
A second, even stronger influence on his life is religion. He was a Member of the Church of England General Synod between 1985 and 1990 and counts among his friends the Right Rev Bill Westwood, the Bishop of Peterborough.
There is more than a streak of puritanism in Mawhinney's character. Famously, he banned the Health Education Authority's Good Sex Guide, describing it as 'smutty'. It is less well known that he vetoed a departmental initiative to sign up Elton John for a youth anti-drugs campaign in favour of the more clean-cut Cliff Richard. As a former member of the National Council of the National Society for Cancer Relief, he is anti- smoking, and he drinks only moderately.
But to portray him as a zealot would be wrong. Mawhinney is a social animal who likes the House of Commons and can often be found in a relaxed mood on the terrace. Impeccably and soberly turned out, the minister will be ready to share a joke in a soft but distinctive Ulster accent.
He has considerable charm and, says one colleague, 'a twinkle in his eye. If you want a lively discussion over a pint, he's your man. On the other hand, if you were thinking about a wild Saturday night on the town, I think I would leave him behind'.
His ministerial route to the Cabinet has taken him through only two departments: Northern Ireland and Health. At Northern Ireland, a department he has a barely disguised ambition to run, he prospered despite his own background. As an ambitious backbencher he influenced the Government in setting up its rolling devolution initiative. His appointment to ministerial office in 1986, after the Anglo-Irish agreement, brought accusations from Protestants that he had sold out.
Nevertheless, he prospered even in the difficult security brief. His phrase-making skills were demonstrated in December 1991 when he declared: 'This is the latest Christmas message from the IRA,' as he surveyed the scene of devastation around Craigavon police station left by a 2,000lb bomb.
At Health he was also renowned as a good communicator and safe pair of hands, bearing much of the brunt of difficult negotiations over the re-organisation of London hospitals. He played a straight bat on difficult wickets.
In the Commons Mawhinney developed an effective dispatch box style, blending the authority derived from a slightly dour Ulster demeanour with political guile. His critics argue that his achievements did not always match up to his presentation. But one Government whip described him as 'a pleasure to work with' - a compliment not extended to all his colleagues - while another MP argued that he 'can spot an elephant trap at 100 yards'.
Even before his ministerial career began, Mawhinney had struck up a rapport with the Prime Minister. In 1979 Mawhinney became MP for Peterborough, the same year Major was elected in nearby Huntingdonshire (the seat is now called Huntingdon), thus joining the 'East Anglian mafia' which includes Gillian Shephard, Richard Ryder and John Gummer. He and Major were members of the Guy Fawkes dining club, which met at a private room in Westminister's L'Amico's restaurant, and was made up of Conservatives from all sections of the party. The Mawhinney/Major friendship is said to have evolved over meals at Peterborough's Bombay Brasserie. At any rate he has remained fiercely loyal.
There are other strands that link the two. Like Major, Mawhinney has proved difficult to pin down over issues that divided the party. One colleague says he has 'never heard him expound his views on economic matters or on Europe. He does not carry a great deal of ideological baggage'.
The new department, which was not his first preference, is therefore in for some tough, sensible but pragmatic management. The ministerial clear-out at Transport leaves the latest Secretary of State carte blanche to review whatever policies he likes. The road- building programme, likely to provoke the wrath of southern Tory voters, might be one place to start. Rail privatisation will remain controversial and the department will have to confront road pricing.
Dr Mawhinney's prescription will include few glitzy initiatives or fireworks. Instead, expect some sensible, sober management and, for a time at least, a few rather jumpy civil servants.