As the election fight for the public service high ground hots up, Conservative leader William Hague has borrowed "from that old song" and branded prime minister, Tony Blair the "Great Pretender" on tax and spending.

"The next Conservative Government will show that the way to improve our public services is to accompany extra investment with real reform - so that the money is not wasted, that it does go to the classroom and the hospital operating theatre and front-line policeman. And day in day out, between now and polling day, in campaigns such as the one we launch today, we will relentlessly expose the broken promises, high taxes and failure to deliver of a Prime Minister who, to borrow from that old song, has become The Great Pretender, " said Hague on Tuesday.

Resisting the temptation to deliver the UK's first karaoke-style political address and drawing on a classic pop number all of 45 years-young, Hague promised the British public that he would "show where the money has really gone - on a huge increase in the cost of Whitehall, on a handover plan to join the euro, on the obscene waste of the dome, and on a comprehensive failure to reform our welfare system and transform our public services."

As both political leaders seize the day for an early start to an expected spring election, Hague's robust speech, accompanying the launch of a new poster campaign, sets out what is sure to be a key tenet of the Conservative campaign, reversing received public wisdom and branding Labour as untrustworthy not just on "stealth" tax - that is a very old tune - but on investment in and delivery of public services.

"Labour governments always think that more taxes lead to better public services. This Labour government has tested that mistaken theory to destruction."

Conservatives will be hoping that their pop-lyric mantra and £1.5 million poster campaign will connect with the public consciousness in the same way as the Saatchi's 1979 "Labour isn't working" campaign. If the lyrics are not yet as familiar as the Platter's original or the Freddie Mercury cover, they soon will be on what may well prove to be day one of a one hundred day plus election campaign:

"The Great Pretender, who pretends that the NHS is improving when anyone who uses it and works in it knows that it is in a state of permanent crisis. The Great Pretender, who pretends that our schools are getting better when parents worry about their children being sent home because of the shortage of teachers. The Great Pretender, who pretends to be tough on crime when its clear to everyone that there are fewer police and more criminals on our streets. People aren't fooled anymore by Tony Blair, the Great Pretender. They have paid the tax and they want to know where's all the money gone. That is what a great part of the next election is going to be all about."

Shadow chancellor, Michael Portillio, followed the Tory leader by warning that Labour's spending commitments had outstripped economic growth leading to a greater tax burden, in contrast he promised: "Conservatives will increase public spending at a rate the economy can afford. We will do that by sensible reforms. The Conservative Party has progressively set out the most detailed public spending plans ever put forward by a party in opposition. Our prudent path for public spending will enable us to cut taxes over the first three years by around £8 billion. Those reductions will be aimed at those who have been hit hardest by Labour: pensioners, savers, hard-working families and small businesses."