David Cameron and Gordon Brown clash over road tax
David Cameron has told Gordon Brown he will be ousted if he does not drop his "deeply unpopular" plans for higher road tax on more polluting cars.
In angry question time exchanges, he challenged Mr Brown: "Don't you understand that if you don't get rid of it, they will get rid of you?"
But the PM said the Tory leader sounded "more like a used car salesman".
Some green groups say the tax should apply to new cars only, rather than all cars bought since 2001.
Owners of some of the oldest cars could face a tax rise of as much as £200 - a move which the Conservatives and many Labour MPs say will hit poorer drivers the hardest.
It's not my backbenchers who are telling me to get on my bike
David Cameron Conservative leader
Mr Brown insisted that 24 of the top 30 models of car would incur the same vehicle excise duty or lower.
But Mr Cameron hit back: "What you are doing is treating the Ford Focus as one model - in fact there are 40 models of the Ford Focus. You've got the saloon and the estate."
He said owners of only three of these 40 models would be better off. "When are you going to stop using such dodgy statistics to back up your figures?"
And as Labour MPs jeered, Mr Cameron quipped: "I don't know why you're all shouting at me - it's the prime minister who's given you the lowest poll rating since Michael Foot."
Mr Brown, who taunted the Tory leader for riding his bike to work while a car followed with his bags, said: "When are the Conservative Party going to be honest when they say they support green taxes and then they run away from every one of them?
"You are sounding more and more like a used car salesman today."
Mr Cameron replied: "It's not my backbenchers who are telling me to get on my bike."
We haven't got a problem with green taxes but they have got to be fair and the retrospective bit of this tax is not fair
Ronnie Campbell Labour MP
He said the road tax rise was "not a green tax, it's a stealth tax". "What on earth is green about taxing someone who bought a Ford Mondeo five years ago?"
Mr Brown replied that the shake up of vehicle excise duty would save 1.3m tonnes of CO2 and increase the number of clean cars.
But speaking to the BBC later, Labour MP Ronnie Campbell said up to 80 Labour MPs were unhappy about the plans and urged Mr Brown to look at the plans again.
He fears they could provoke a backlash similar to that against the abolition of the 10p tax rate.
"This affects working people with second-hand cars. When they have to come next year and renew their road tax, they are going to get a pretty big shock when they have got another £100, £150 to £200 to pay," he said.
"We haven't got a problem with green taxes but they have got to be fair and the retrospective bit of this tax is not fair."
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