Gordon Brown's package hardly fell into the category of a blatant bribe to the electorate, but the measures he announced on Tuesday could be seen as a pointer towards a possible election in spring 2001.

A number of the tax changes he set out to the Commons over a glass of Highland Spring mineral water are designed to kick in in April 2001, feeding through into pay packets a month later.

The timing could be highly significant, since Number 10 has always worked on the assumption that Mr Blair could go to the polls in the spring of 2001 - four years into his term.

Mr Blair is not about to repeat the mistake of Jim Callaghan, the previous Labour prime minister, who delayed holding an election to the end of his five-year term in May 1979. The so-called "winter of discontent" guaranteed his defeat.

Kenneth Clarke, the last Tory chancellor, used to say that good economics were good politics. But few residents of 11 Downing Street can resist a splurge as polling day approaches.

Even Mr Clarke himself is not totally immune to the charge of allowing the electoral cycle to influence good economic stewardship. Why else did he fail to put up interest rates in the run-up to the 1997 general election?

Mr Brown's Budget hardly represents a reckless opening of the sluice gates in the run-up to a 2001 election, but it is cleverly designed to enhance a feeling of well-being in the months leading up to the poll.

While taking money out of the economy through a range of indirect taxes, the stealthy chancellor is putting it back into people's wallets where they actually notice it.

The child tax credit will be introduced in April 2001, putting around £1.4bn into the pockets of families, even if it is offset by the scrapping of the married couples' allowance.

Changes to the national insurance regime will also come into effect at the same time, representing an effective tax cut to low and middle earners. Meanwhile, the new 22p tax rate, introduced in April 2000, will be relatively fresh in the memory.

If Mr Brown has a target voter in mind for his pro-posals, he is "Sierra man", the C2 family man living in a "swing constituency" somewhere in the Mid-lands.

Julian McCrae, an economist at the Institute for Fiscal Studies, said whatever the swings and roundabouts of Mr Brown's latest Budget, it was clear that the chancellor had delivered help to his target group.

"There were an awful lot of changes in the Budget, but the group who clearly benefit are families with children," he said.

The Conservatives, who have labelled Mr Brown "the pickpocket chancellor", hope people will notice that while more money is coming into their pay packets, more is going out through other taxes.

But they accept that some voters may not look beyond the bottom line on their pay slip.

"Gordon Brown is trying to present this as a giveaway Budget and hopes the figures are so misleading that nobody will notice," said a spokesman for William Hague, the Conservative party leader.

"I think the public are more savvy than that - they know the money has got to come from somewhere."

If Mr Blair is planning a 2001 election, the measures announced by his chancellor this week may be the first down-payment in a much larger pre-election handout.

After all, he will have at least one more Budget to introduce new tax cuts, in addition to the ones that are already going to come into effect in April 2001.

However, Mr Brown is unlikely to blow his economic strategy out of the water in the interest of short-term electoral gain in the manner of some of the previous holders of the battered Red Box.

For instance, Reginald Maudling recklessly cut taxes in a failed attempt to secure a Tory election victory in 1964, and left the Labour party to clear up the mess.