Charles Kennedy has repeated his call for the government to scrap the council tax.

The Liberal Democrat leader challenged the prime minister in the Commons, claiming the tax had risen by 70 per cent since 1997.

"How can the prime minister justify that, particularly to pensioners?" he asked.

But the prime minister placed responsibility firmly with local government, arguing funding had gone up "adequately" by 25 per cent in real terms.

"Our policy is to make sure we give help to local government - and we are," said Tony Blair.

Kennedy said it was time for the annual charge to be replaced with a form of local income tax.

"Wouldn't it be better to scrap the unfair system and replace it with one based on people's ability to pay?" he asked.

Blair, however, turned his fire on the Liberal Democrat's policies - saying the party's proposal amounted to a six pence rise in income tax.

The Lib Dems, said the prime minister, had over 70 separate spending pledges.

"My favourite is this - this is commitment 65, funded training for teachers and specialists on sex education: providing them with information and material to aid honest, non-judgmental and thought-provoking lessons," said Blair mockingly.

"Let me suggest commitment 71 should be funded training for Liberal Democrat Treasury spokesman to aid honest, non-judgmental and thought provoking lessons on financial discipline."