Environment secretary refuses to deny plans to cut regulations. Source: Parliament TV Parliament TV

The environment secretary, Caroline Spelman, has refused to deny that the Cabinet Office is proposing to rip up of thousands of pages of environmental regulations and guidance as part of the government's "red tape challenge". The proposal, revealed by the Guardian, is understood to be led by Oliver Letwin and is causing deep concern among green MPs and campaigners.

It follows the cutting of planning regulation guidance from 1,000 pages to just 50 pages, which sparked a national outcry last year. According to a well-placed source, Letwin allegedly told senior environment officials at a meeting on 12 January that the planning proposals showed how the cutting of guidance could "work very well" and said he wanted the same for environmental regulations.

Under sustained questioning about the proposal from MPs including Caroline Lucas and Zac Goldsmith at a select committee meeting on Wednesday, Spelman said: "I am not in a position to confirm or deny the story. I was not at the meeting." Goldsmith said Letwin's proposal was causing "huge concerns".

Spelman said the Cabinet Office was the lead department on the red tape challenge and it was now considering its response on environmental regulations. Spelman told the environment audit committee that the purpose of the red tape challenge was to reduce the burden of regulation on businesses while preserving the purpose of the regulation.

Lucas said: "I don't know which is more worrying – the fact that Letwin has reportedly proposed slashing all environmental guidance so it fits into a 50-page document, or that the secretary of state for the environment appears to have had no knowledge of it. If the red tape challenge is to be a genuinely consultative process, the government must listen to what the vast majority of people responding to the consultation are actually saying – that they value laws to uphold environmental protection, and do not want to see them ripped up."

"Spelman had every opportunity today to deny rumours that the government is planning to tear up the laws that protect our health and environment, and replace them with 50 pages of meaningless guidance," said Craig Bennett, director of policy and campaigns at Friends of the Earth. "This would be the environmental equivalent of taking the complete works of Shakespeare and summarising it as a tweet."

At the 12 January meeting, Letwin met senior officials from the Department of the Environment, Food and Rural Affairs (Defra) along with representatives from the Environment Agency (EA) and Natural England. According to the Guardian's source, he told officials he wanted all environmental guidance replaced with a single 50-page document just as the government is doing with planning . The proposal was apparently met with "disbelief".

Defra and the Cabinet Office declined to comment on the meeting but the EA told the Guardian: "The meeting was about simplifying advice to business about environmental regulation and was positive."

The red tape challenge on environmental regulations included all existing rules including those protecting against air and water pollution, industrial discharges and noise. It also included protection for wildlife, landscapes and recreation. The website states: "We have to make sure that our … environmental regulations are not strangling businesses and individuals with red tape." It asks visitors, among other questions: "should we scrap them altogether?"

However, according to a Guardian analysis, 97% of the responses expressing an opinion in the "air pollution" and "biodiversity, wildlife management, landscape, countryside and recreation" categories demanded no changes or stronger protection for the environment.

Tom Burke, veteran environmentalist, previous adviser to Conservative environment secretaries, and now working for Rio Tinto, said: "This report [of the Letwin meeting] is consistent with a complete hostility to the environment, based on the misapprehension that the environment regulations get in the way of growth – which they don't and there is no evidence that they do – and the mistaken belief that the British people want to choose between the two, which they don't."

Some business leaders, including Neil Bentley, the deputy director general of the CBI, have also spoken out against environmental deregulation, following attacks on regulations such as the EU habitats directive by the chancellor, George Osborne.

"Environmental regulation doesn't have to be a burden for business. Framed correctly, environmental goals can help our economic goals - help start new companies and generate new jobs and enrich us all," he said.

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