Leading article: Mr Osborne has given the voters something to chew on

With George Osborne's announcement that the Tories will use spending cuts to finance a reduction in National Insurance, a still unofficial election campaign is beginning to catch fire. True, the decline of the Tories in the polls and the loss of their earlier commanding double-digit lead had already turned a dull, predictable Tory shoo-in into a genuine contest whose likely winner was unclear. But now, with a fight on their hands, the Tories are having to abandon their policy of sticking to bland Obama-like generalities about the desirability of "change" and make some precise commitments about what they intend to do in government.

This is no happy place for an opposition whose strategy until now was predicated on little more than pointing out the evil ways of Gordon Brown's government. Instead, David Cameron's team is the one sweating under the spotlight and feeling pinned down on the economy. Both the Tory leader and his putative Chancellor, George Osborne, must be forgiven for feeling life is unfair. The recent Budget showed Labour is just as opaque and mysterious over what must be done to sort out the country's finances and reduce public debt.

Thus far, Conservative attempts to shed some light on their policies and put clear blue water between them and Labour on the economy have not borne much fruit, as the muddle over proposed changes to the marriage allowance demonstrated. To add to their nervousness, the economy has now let them down, obstinately declining to expire under Labour's supposedly disastrous care.

Cameron and Osborne were always going to have to tread carefully here, staying on the right side of a line that separates gloating from regret. Now they are having to hastily concoct a new script altogether: the latest economic figures indicate a slight improvement. Unemployment is lower than expected; debt has fallen, marginally. None of this plays well for the opposition. The Tories don't want to look like spoilsports, but nor do they want to credit Mr Brown or Alistair Darling for modest changes for the better that they believe have occurred in spite of their actions, not because of them. In the meantime, polls are starting to suggest more people trust Labour than the Tories on the economy.

Hence the latest initiative. Desperate looking though it may be, as an attempt to get the Tories off their defensive position, Mr Osborne's reform of National Insurance is still worth considering. He is right to say National Insurance is a tax on ordinary people not on the rich, and that it is a stealth tax and a tax on employment, when it is no time to make employment more expensive.

Above all we should welcome this debate because the more sensible discussion we have on tax reform and on the Budget in the next few weeks the better. Neither main party has been remotely honest on the economy. Each clearly hopes to delay the delivery of bad news until after the election, by which time the winner is in office, and has years to sort matters out.

This is the worst kind of cynical, strategy-driven party politics, and is ultimately subversive of the democratic process because it alienates people by being so patronising, insulting the intelligence of the average voter who does not want to be fed a diet on pulpy political platitudes.

We all need to be made aware of the difficult times that certainly lie ahead, not be shielded like infants. By throwing National Insurance into the ring Mr Osborne has done the country a favour by giving voters something to chew on. Let's hope this marks the beginning of a trend; it will make for a better election if it does.