Big lies have a cynical logic. It is the little lies, the correctable mistakes, that seem so pointless. Why bother getting it wrong when getting it right would do no harm?
Take the apparently trivial case of Brian Mawhinney, the Secretary of State for Transport, and the Manchester trams. To Mancunians, the sleek new trams are a source of great civic pride. As they slip along, from Altrincham in the south to Bury in the north, they make Manchester seem bright and modern in comparison with dirty, old-fashioned cities such as, say, London.
Dr Mawhinney in television studios, on the Today programme and in speeches has been criticising the Metrolink for several months, not in a spirit of bitterness but in a tone of wise scepticism. He has nothing against the trams themselves - they have been an "enormously successful project", he told the pressure group Transport 2000 last month. But after spending £140m on the line, Metrolink had taken "just three cars in a thousand" from Manchester's roads.
The gleaming trams - safe, inexpensive, reliable and profitable - were all very well but most people did not want to use them.
The Government had to strike a balance, he went on, between the need to protect the environment and the need to keep society mobile. Above all, it had to recognise that people liked cars. "Given the choice" on ways to reduce carbon monoxide pollution, "many people may prefer to lag their boiler or insulate their loft rather than buy a smaller car."
Dr Mawhinney's use of statistics is subtle and appeals to our gut instincts. In our hearts we know most of us would rather drive. Yet his figures are utterly misleading. The calculation that just three in a thousand car journeys have been cut by trams uses as its base all car journeys in the Greater Manchester conurbation, from Oldham to Stockport, Tameside to Wigan.
But Manchester does not have a tram network covering the whole of the metropolitan county. It has just one line and just 26 trams. To build it, Manchester closed a railway line which was already carrying people by train instead of car.
A much fairer calculation is to look at cars using the roads running parallel to the tram route since the service started. Manchester City Council did just that and found that traffic had been reduced by 10 per cent or 100 in 1,000 car journeys. This is impressive. It is also not in the least surprising to anyone who lives in Manchester. The trams have been a success. When they replaced the creaking suburban railway lines from Bury and Altrincham, the number of public transport journeys on the route doubled to 13 million.
Dr Mawhinney has form for this misuse of statistics. Last year he kept saying that improving the main railway line from St Pancras in London to Sheffield in the north would cut traffic by only 1 per cent. Transport 2000 pointed out to him that the calculation was based on traffic on all roads between Yorkshire and the capital, even those which ran from east to west, such as from Peterborough to Norwich.
Which still leaves us with the question: why does he bother to get it wrong? Dr Mawhinney is in many ways an admirable man. He will go down in history as the first transport secretary to shift resources away from the car. He has abandoned road building and widening schemes. Last week the proposal to turn the M25 into a 14-lane, American-style superhighway was dropped. The Government has moved, very late in the day, to stop the growth of out of town shopping centres; it has spent more on bus routes; it has even authorised £3m for cycle lanes in London.
It may be that Mr Mawhinney is not deliberately misleading the public, although Manchester City Council has repeatedly protested - with no effect - to his private office about his much-quoted figures . But whether it is a mistake or a little lie, it is still revealing. The Government has moved away from Margaret Thatcher's evangelical enthusiasm for "the great car economy", but still cannot bring itself to believe that public transport can work. Like a reformed alcoholic, it acknowledges that its past life was mistaken but can see nothing in the future that will be as satisfying.
So cheap and sensible measures that could encourage people out of cars are ignored. Transport 2000 has put forward plans for bus-rail interchanges, through-ticketing and a national integrated timetable which could form the basis of a national transport policy and allow travellers to plan with confidence. Nobody at the Department of Transport is interested.
Phil Goodwin, director of Oxford University's Transport Studies Unit and a Department of Transport adviser, pays tribute to the Tories' policy changes but adds that Britain is 10 to 15 years behind the rest of Western Europe. Plans to pedestrianise city centres are still handled slowly and with suspicion. Money is still needed to make the less congesting and less polluting transport more attractive.
Ministers are still not prepared to gamble that people will desert their cars for public transport if trams, trains and buses are made clean and efficient. Indeed, after deregulating the buses and privatising the railways, they may have thrown away the power to improve the system.
Manchester has run into this wall of indifference. It would like to make the city less congested and polluted by building a proper tram network. But the remnants of the Government's old ideology hold it back and hold back all the other cities that would like to follow Manchester's example.
The Government has insisted that any new lines must be built with contributions from the businesses which will benefit from improved access (a requirement which does not apply to new motorways). In some cases the demand can be met. Money can be raised for lines that businessmen and developers need such as one to Manchester airport and a second to the empty offices in the old Salford docks, which like their counterparts in London seemed a great idea when they were built in the 1980s.
But the private sector is not interested in a far more important line to Rochdale and Oldham. Hundreds of thousands of commuters would use it, but it goes through residential areas not past office blocks and factories with owners who are ready to put their hands in their pockets.
Officials in Metrolink, who are justifiably proud of their achievement, rage against the Government's failure to understand the wider benefits of public transport. "I know we can make that line work," said one executive. " I know we can make a profit, but they just won't let us try."Reuse content