Charles Kennedy has accused the prime minister of misrepresenting the Liberal Democrats' tax policies.

Kennedy has written to Tony Blair in an attempt to "put the facts on the record".

In recent clashes in the Commons, the prime minister has accused the Lib Dems of being "dishonest" about their plans.

He has said the party is committed to spending £15 billion on pledges such as ending prescription charges, helping small businesses and paying benefits to students during the summer holidays.

But Kennedy insisted that raising the top rate of tax to 50 per cent for those earning £100,000 a year and over would pay for his party's carefully costed policies.

"At prime minister's question time on Wednesday, you again misrepresented Liberal Democrat spending commitments and our policy on tax," he wrote.

"This is not the first time you have chosen to mislead people over our policies and I feel it is now important to write to you to put the facts on the record."

Kennedy said that of the £4.7 billion that would be raised by the tax hike, around £2 billion would be spent on universities and £1 billion on personal care for the elderly.

The remaining £1.7 billion would be spent on cutting council tax bills while the party switches to a new system of local income tax.

"These are our sole commitments for this money and they will not change before the next election," Kennedy wrote.