SCOTLAND'S GREEN watchdog held back an attack on polluting farmers after it consulted government spin doctors.

According to internal documents obtained by the Sunday Herald, the Scottish Environment Protection Agency (Sepa) completely rewrote a draft news release after circulating it to ministerial media officials.

One accusation - that farmers' leaders were being "misleading" - was left out in favour of comments about the key role of agriculture in protecting the environment.

Environmentalists have since accused Sepa of being "muzzled" by ministers so not to offend the powerful farming lobby - an accusation denied by both Sepa and the Scottish government.

Emails disclosing communications with the former Scottish Executive were released by Sepa last week after an investigation by the information commissioner, Kevin Dunion. The Sunday Herald requested the documents under Freedom of Information laws in August 2006.

In July 2006, Sepa was preparing a response to a new "regulation action group" being launched by the National Farmers Union Scotland (NFUS). Farmers were angry about what they saw as "unnecessary red tape" imposed by Sepa and other regulators.

A draft news release was circulated within Sepa and to the head of environment media at the Scottish Executive. It explained at length all the consultations that had taken place with farmers.

"Sepa is concerned that some of the examples of red tape provided by NFUS are misleading," it said, going on to take specific issue with four claims made by NFUS. One - that field stones had to be treated as "dangerous waste" - particularly annoyed Sepa.

"Sepa has never said that field stones are waste, except when they are being dumped in landfills," said the draft.

When the release was issued on July 24, 2006, these points had vanished. "Sepa welcomes the creation of a regulatory action group by NFUS and looks forward to being involved in its work," it said.

Green MSP Robin Harper said that for Scots to respect an independent organisation like Sepa, it needed to be free from ministerial interference. "There would be no point establishing a watchdog and then muzzling it," he said.

He was backed up by WWF Scotland's acting director, Dr Dan Barlow. "It is vital a government watchdog charged with protecting Scotland's environment is able to speak out about issues of concern," he said."

The Scottish government said that although it worked closely on communications with all its environment agencies, it was each agency's responsibility to make the final decision on content.

According to Sepa, it had decided on the final wording after pursuing the usual good practice of consulting widely on public statements before issue. "It is no secret there had been public disagreements between Sepa and the NFUS in 2006," said a Sepa spokeswoman.