The group said not enough has been done to stop illegal landings

The Fish Trade Equal Opportunities Group said ministers have failed to stop �80m worth of "black fish" being landed by crews without valid licences.

It said it is consulting counsel over possible legal action against the Scottish Executive.

However, the executive defended the record of the Scottish Fisheries Protection Agency.

The group said it has sent a letter setting out its intention to start legal proceedings to Fisheries Minister Ross Finnie, with a copy also sent to the SFPA chief executive Paul Du Vivier.

George Hosie, an Aberdeen fish merchant and joint leader of the 12-strong group, said he felt the executive was not committed to eradicating illegal landings.

In the last year, the SFPA have carried out over 27,000 catch inspections Scottish Executive spokesman

He said: "The executive know the problem exists yet they choose to do nothing about it.

"There is a considerable section of the industry who are suffering great hardship.

"It's all about weak or non-existent enforcement by the SFPA, overseen by their political masters, the Scottish Executive.

"They are either unable or unwilling to address the problem and it's forcing people in the fishing industry to break the law simply to survive."

Mr Hosie said that about 5,000 fishing industry jobs had been lost in Aberdeen alone in the last 10 years and claimed that the North Sea had been left virtually empty of stocks as a result of poor implementation of quotas.

The merchants said they have written to Fisheries Minister Ross Finnie

He demanded immediate action to protect the remaining jobs.

Robin Harper, co-convener of the Scottish Greens, supported the group.

He said: "It is clear the executive has been well aware of the problem over the last six years and has done nothing effectively to deal with it.

"The loss to the exchequer is nothing compared to the damage to fish stocks and the blatant undermining of fisheries policy."

An executive spokesman said: "The SFPA inspects catches at point of landing to ensure they are properly declared and recorded.

"In the last year, the SFPA have carried out over 27,000 catch inspections.

"Their activities prevent an estimated 500-700 tons of whitefish being landed illegally every month.

"In addition, post-landing investigations involving processors and merchants are carried out into catches not inspected at point of landing where there are reasons to suspect under-declaration of fish."