Lord Lester's opinion was sought by the Law Society

Lord Lester of Herne Hill said the Legal Profession and Legal Aid Bill was not compatible with human rights law.

The Scottish Executive proposals, being considered at Holyrood, are aimed at increasing public confidence in the handling of complaints against lawyers.

Ministers said they would consider his opinion, although they believe the bill complies with human rights legislation.

Lord Lester's opinion was sought by the Law Society of Scotland, which has argued that the bill will not work in its current form.

The opinion states that there is insufficient right of appeal for the public and that the proposals compromise the independence of the legal profession in Scotland Douglas Mill Law Society of Scotland

The society regulates the country's solicitors and handles complaints about their conduct.

It has voiced support for the creation of an independent body to investigate complaints, but raised concerns about the funding of the scheme and whether it would comply with human rights laws.

Lord Lester concluded that the new body would not be compatible with the European Convention on Human Rights (ECHR).

He said clients and solicitors would need to have the right of appeal to a court or tribunal.

Douglas Mill, the chief executive of the Law Society, said: "We have called for an independent body to handle service complaints against solicitors in Scotland, but also made it clear that any new system must not only work but also be an improvement on the present system to the benefit of the public and the profession.

Ministers will assess the position very shortly and will be happy to discuss it with the Law Society of Scotland Scottish Executive spokeswoman

"We obtained Lord Lester's opinion after repeatedly raising our concerns about compliance with human rights law with the Scottish Executive.

"The opinion states that there is insufficient right of appeal for the public and that the proposals compromise the independence of the legal profession in Scotland."

An executive spokeswoman said the bill would improve the transparency of legal complaints handling.

"Like all bills introduced into the Scottish Parliament, the Legal Profession and Legal Aid (Scotland) Bill was certified as ECHR-compliant by ministers and the presiding officer.

"We are considering very carefully the opinion put forward by Lord Lester.