UK efforts to cut greenhouse gas pollution are "seriously off-course", an influential MPs' committee has said.
Landfill tax rises "not enough"
Attempts to use taxes to shift people away from damaging the environment are at risk of stalling, according to the Commons environmental audit committee.
The Treasury denies the claims - pointing to what it says are "factual inaccuracies" about the amount of carbon dioxide emissions.
The committee, which is chaired by Conservative MP John Horam, says green schemes unveiled by Mr Brown in his pre-Budget report are hardly major initiatives.
"This reinforces the impression that the Treasury's strategic objective of shifting the burden of taxation from 'goods' to 'bads' is in danger of stalling," it says.
"Indeed, we see little evidence of an environmental tax strategy as such."
Mr Brown promised that the landfill tax would rise by £3 per tonne per year from 2005-6.
We are astonished by the views the transport secretary has recently expressed about the environmental impact of aviation
Environmental audit committee
That has failed to impress the MPs, who say it will take at least nine years for the tax to reach £35 per tonne - seen as the minimum level for changing behaviour.
The tax increases should be steeper than currently proposed, says the committee.
The report accuses the Treasury of trying to perpetuate the "myth" that the government's climate change strategy is on track by using outdated figures for carbon dioxide emissions in the pre-Budget report.
"The climate change strategy for reducing greenhouse gases is seriously off-course, and current progress and future projections must be reviewed as a matter of urgency," it says.
A Treasury spokesman instead pointed to figures published last week shwoing a 3.5% fall in UK carbon dioxide emissions in 2002, "putting us on course to meet climate change targets".
The MPs argue the government's 10-year transport plan is especially unlikely to yield the pollution cuts initially predicted.
And they take special aim at the transport secretary's recently reported comments dismissing a Royal Commission's idea of using taxes to take account of the environmental costs of aviation.
Mr Darling reportedly said: "The commission's remedy was to try to price people off planes. I think they might have some difficulty selling that proposition."
Those views "astonished" the committee, which accuses Mr Darling of trying to pre-empt the Treasury's consultation on the issue.
"His comments demonstrate a failure in the mechanisms which the government has put in place to embed sustainable development at its heart," say the MPs.
They were particularly surprising because of the prime minister's emphasis on green issues in a recent speech, they argue.
Fuel duty has proved the most controversial green tax in recent years, especially in the wake of the blockades in autumn 2000.
The MPs call for a more coherent approach to fuel duties, and especially suggest insufficient incentives are being provided for people to use bio-fuels.
They also criticise the "perverse" tax incentives for building on brownfield and greenfield sites.
VAT does not have to be paid on new housing but is applied at the full 17.5% rate for renovations and rebuilds on brownfield sites.
That issue needs more research, adds the committee.
The report suggests environmental taxes still raise very little money and ought to be used more.
"If the huge scale of the environmental challenges facing us is to be addressed, environmental taxes and fiscal incentives will need to play a far larger part that they currently do," add the MPs.
The Treasury spokesman said fuel duty cuts had been set to reflect their green benefits.
"We are also working on aviation, and have started a discussion with the industry and environmental groups to see how the environmental costs of aviation can be taken account of and where appropriate, reduced," he said.
Reductions or exemptions to the main rate of VAT were also in place to encourage reuse of existing properties, as well as for decontainating former industrial sites, he said.