Charles Kennedy has accused Gordon of doing too little too late to turn around public services.

The Lib Dem leader - who is banking on taking the public sector delivery high ground as his party carves out a new role in opposition - told the BBC that Labour had been too slow to get funding into essential services.

He said that the extra cash would take too long to deliver improvements.

"Gordon Brown for most of the last parliament persisted with under-investment, which means that even though this money is going in, and welcome though that is, it is going to take a long time before we see the tangible benefits," he told the Frost programme.

The Lib Dems are set to back tax transparency on health.

Kennedy is trailing a clear link between health spending and taxation to restore voter faith in government.

"One of the ideas that I am floating within the party at the moment, we will debate it at the conference in the autumn, is earmarking a specific tax for the health service, so that people see where the money is coming from and see what it is being deployed in favour of."

And Lib Dem Treasury spokesman, Matthew Taylor warned that Labour's centralising instincts could not be trusted.

"You can't trust Labour to spend money well. Their instincts are to try to control everything from the centre. The government must trust the teachers, doctors and nurses and the police - not waste money on Westminster and Whitehall red tape," he said.