The Liberal Democrats go further. They have a cunning plan about how to pay for a bigger and better education system. They will put a penny on the basic rate of income tax to raise nearly pounds 2bn a year.
Painful truths are a Lib Dem speciality. Improved education is essential for the future of the British economy, it is an investment in our future and it will not come free. They are the only party to spell out where the money for improvements will come from.
A penny on tax does not sound all that much to the typical voter, especially when missing the key phrase "in the pound". It adds up to pounds 180 a year - or nearly pounds 3.50 a week for somebody on the national average salary. This is nearly two pints of beer in Sedgefield, or a glass of decent chardonnay in an Islington wine bar - reasonable people would probably be prepared to make that weekly sacrifice for our children's future.
In a recent speech, Malcolm Bruce, the Lib Dem Treasury spokesman, spelt out the party's education priorities. Nursery education for all three- and four-year-olds whose parents want it, more books and equipment, decent schoolbuildings, and, especially, attracting the best and the brightest back into the teaching profession.
The extra penny will raise pounds 1.7bn in a full financial year. Suppose it is all spent on raising teachers' salaries to lure back all those talented people we all know who have given up teaching. It would amount to a generous 15 per cent pay rise. On the average teacher's salary of about pounds 20,000, that is an extra pounds 3,000 a year. Party on!
Of course, that would leave all the other priorities. Wages and salaries form the biggest single chunk of the education budget as teaching is such a labour-intensive activity. Increasing the number of teachers to reduce class sizes would be equally cash-consuming. Perhaps the teachers' pay bill had better go up by only 5 per cent, or pounds 1,000 a year. That is about pounds 12 a week after tax and national insurance, or six and a half pints of beer.
That would leave about pounds 1.2bn a year for other priorities. This is enough, indeed, to raise capital spending on school buildings and equipment - think of all those computers needed in the modern classroom - by about a third.
But the bottom line is that pounds 1.7bn a year is not very much money compared to the cumulative total required to fill in a hole left by years of underfunding - especially when the Lib Dems have also earmarked the penny-in-the-pound tax increase to pay for extra NHS spending, their other priority.
It is not easy to say how big the funding hole is, for education spending has actually risen in real, inflation-adjusted terms every year since the Conservatives came to power, except for the past two when it has been virtually flat. The real problem is that, as with the NHS, the demands and expectations we are placing on the education system have risen, too.
So, for example, entrance to higher education has doubled since 1989 to include three in 10 of all young people leaving school or further education. The Liberal Democrats, like Labour, say they want to increase this proportion and expand the number of adults in higher education.
Schools clearly feel that they are struggling to meet the demands placed on them by the National Curriculum and testing. Which parents do not know of the extra tax already imposed by all those "voluntary" charges that schools must make for trips and special events? Then there is supporting fund-raising events such as the summer fete. There must be a squeeze if the nation's primary schools are having to buy their computers courtesy of Tesco and Sainsbury.
All our politicians are guilty of not addressing the most difficult issue they face - if total government spending can rise, at most, at the same pace as the economy expands, what is to be done about the fact that our demand for public services is increasing much faster? The honest, plain- spoken Liberal Democrats are doubly misleading us by pretending that a small increase in tax rates will solve the problem.
It is not enough to say that education and health are priorities and will get the extra cash. It is not enough extra cash. Perhaps 5p in the pound would be, perhaps not. A penny is peanuts.
The language of priorities will have to be applied within education, too. If teachers are the most expensive part of our children's education, perhaps there should be fewer of them. Spend the pounds 1.7bn a year on mechanising schools. Increase class sizes, install many more computers with Internet connections and more video links to distant lecturers, and let Mr Bruce advise the nation's best and brightest to retrain as software developers rather than teachers.