The Chancellor, Mr Gordon Brown, was under continuing pressure over Labour's spending plans yesterday as the Prime Minister, Mr Blair, confirmed that the party's election manifesto would pledge not to raise income tax.
The second successive day of tax-and-spend rows eclipsed Labour's plan to throw the spotlight on figures showing the latest fall in hospital waiting lists, enabling the government to claim delivery on one of its five key pledges at the last election.
As the Chancellor battled charges of a £5 billion "black hole" in his spending plans for the latter part of the next parliament, the Conservative leader, Mr William Hague, eagerly turned up the heat on the government over tax.
Speaking at the launch of his party's Scottish manifesto in Edinburgh, Mr Hague challenged Mr Blair to say that there would be no tax increases if Labour won the election.
"If he is not prepared to say that, everyone will know that he plans yet more stealth taxes on the people of Britain."
The shadow chancellor, Mr Michael Portillo, was also on the defensive over the Tories' £8 billion taxcutting promise, after the shadow social security spokesman, Mr David Willetts, appeared to lose one-eighth of that in the course of an interview with the BBC's Newsnight. But the pressure was on Labour as attention continued to focus on the warning by the respected Institute of Fiscal Studies. This suggested that the Chancellor would have to raise taxes if he was to sustain the annual 3.8 per cent increase in spending on public services beyond the first three years of the next parliament.
The Liberal Democrats leader, Mr Charles Kennedy, accused Labour of being timid over tax and of "a terrible poverty of ambition".
Speaking in Manchester on the third day of his countrywide tour, Mr Kennedy said if Labour wanted to be really radical and if it felt it necessary and appropriate to increase taxation for social or economic reasons it should say so and keep that option in reserve. "But they are so timid in government that they won't."
The Chancellor insisted that he would not break his "fiscal rules" but again refused to say whether the government would keep up the same level of spending on public services after 2003-04 when, under current projections, the rate of growth is set to fall back from 3.7 per cent to 2.5 per cent.
Mr Brown said on Thursday that the government had not made commitments to increased spending at the higher rate during the final two years of the next parliament. The Tories in turn had asked how this squared with Mr Blair's suggestion that health, schools, transport and the police would need seven or eight years of sustained extra investment.
Labour yesterday sought to dispel suspicions of a behind-the-scenes disagreement between the Prime Minister and his Chancellor over the specific terms of Labour's manifesto commitment on taxation. Party sources insisted that the first draft and the final draft on tax were exactly the same.
That followed a broad hint from Mr Blair that Labour did intend to repeat its 1997 tax pledge, despite the reported views of some senior figures that, having established their economic credentials, Labour had no need to be so specific a second time.
The Prime Minister again repeated yesterday that Labour is seeking re-election on the basis of its economic record. He told voters: "The single most important thing is the stability of the economy. If you want to vote for me or not vote for me as prime minister, do it on that basis."
As Mr Portillo launched the Conservative's London manifesto, Labour sent an advertising van to the event showing a 16-year-old William Hague at the Tory conference under the slogan: "Someone didn't do his homework. Who thinks the Tory manifesto sums add up? Just William."