The Law Society has advised legal aid firms not to take part in the Legal Aid Board's green form block funding pilot project amid anger over the LAB's handling of the scheme.
Members of the Law Society's council passed a resolution "recommending" firms to shun the scheme at a full council last Thursday.
The pilot project, involving 145 firms, is due to start in June, but the Law Society claims firms taking part will have to undertake a huge amount of unpaid administrative work.
The council heard how participating firms would have to install monitoring systems to ensure they do not overspend on their contracts, and will also have to spend time on documentation and in meetings with LAB researchers.
"This is another bad legal aid deal for the profession," said council member Geoffrey Sandercock. "Let us send a clear message to the Legal Aid Board that we are fed up."
Opposition to the scheme also came from council member Angus Andrew, whose London firm Osbornes is involved with the pilot project. He said the firm may withdraw from the scheme.
Jon Lloyd, Legal Aid Practitioners Group co-chair, backed the society's stance, saying that the green form contract was one-sided and not a partnership between the LAB and franchised firms.
But the LAB remained positive about the prospects of the scheme beginning as planned in June.
A spokeswoman said that so far there had only been one meeting with the society about the green form contracts and the LAB had already agreed to change some aspects of the wording, but she refused to comment on what they were.