Tony Blair reiterated his claim yesterday that the Conservatives would divert £1bn away from the health service to subsidise operations in the NHS.

Despite being labelled a "liar" by Michael Howard over the issue, the prime minister argued that Conservative proposals to subsidise private sector treatment would create "two classes of NHS patient", with faster treatment available only to those who could afford to pay.

He said Tory plans would effectively end the principle of treatment according to need and replace it with "treatment according to wealth".

"Mr Howard has asked us to withdraw the allegation," Blair said. 

"We will not. It is his policy not ours and if he is embarrassed by it, is up to him to withdraw the policy."

Blair went on to highlight Labour plans to improve child health by giving all children access to a school nurse, cutting fatty and salty foods from school meals, introducing clearer food labelling, restricting advertising of unhealthy food to children and expanding sport at school.

Cherie Blair, who was campaigning with her husband, later said she may send their five-year-old son to school with a packed lunch if the standard of school food does not improve.