The rural affairs department is failing to deliver on its environmental promises, according to Liberal Democrat spokesman Malcolm Bruce.

Launching the party's green Budget on Thursday, he said that secretary of state Margaret Beckett had refused to meet the party to discuss issues such as climate change.

"We as a party are frustrated about the environmental agenda and the government's inability to deliver beyond the rhetoric in many areas. We think we have a lot of very workable policies," he said.

"We are perfectly willing to engage with the government on this, but I think we find the government is more willing to contribute to outside meetings than actually produce policies that are advanced.

"You are actually talking about a government that is closing down the agenda rather than opening it up."

Director of policy at the WWF, Andrew Lee, agreed.

"The government's international rhetoric on environmental issues is strong outstrips its domestic performance," he said.

Policies contained in the budget, which have the approval of the WWF, include reducing vehicle tax for the most environmentally friendly and establishing a Green Tax Commission to consider tax reform aimed at making the system "greener".

A carbon tax, especially supported by WWF, would also replace the climate change levy which the party considers to be "overcomplicated and bureaucratic".

The level of VAT on new house build and renovation would be equalised with a reduction for greener materials, while a National Recycling Programme would be implemented over four or five years, aiming to increase the level of recycled household waste to 60 per cent.

Policies also include reallocating the landfill tax credit fund to environmental projects, such as recycling, while the landfill tax itself would be gradually increased.

A greenfield levy would be imposed, at a level set by local authorities, which would be targeted at improving wildlife and brownfield sites.

The party accused the Department for the Environment, Food and Rural Affairs of failing to deliver.

"Liberal Democrats are committed to an environmentally responsible future for Britain. The green agenda must be placed at the heart of government, with green taxation to promote environmentally friendly policies," said Bruce.

"Environmental responsibility should be at the heart of government and at the heart of Britain's daily life. By failing to stress the importance of green issues Defra is failing Britain."