Dan Brennan QC said a legal ombudsman could ensure that Lord Irvine of Lairg's proposals to shake up the law did not result in the justice system becoming unbalanced and unfair.
"It seems remarkable that we have watchdogs to determine the reasonableness of gas and electricity prices but not the standards operating in a nationwide legal system," he said.
The idea of a legal watchdog will be proposed by Lord Ackner in an amendment to the Access to Justice Bill which begins its committee stage in the House of Lords tomorrow.
The Lord Chancellor is facing a concerted rebellion from peers over several elements of the Bill, particularly his plans to give himself greater powers.
The Bar Council, working in alliance with the Law Society and the Consumers Association, has assembled a cross-party group of peers who have tabled over 50 amendments.
Mr Brennan said: "Theoretically you could finish up with a system whereby the government decided who prosecuted, who defended, how they were regulated, how they were paid and which citizen should get legal assistance. I'm sure the government does not intend that to happen but we want to make sure the Bill does not leave it open for that to happen."
The challenges will concentrate on proposed new powers for the Chancellor, which would give him control over the independent legal professions prompting fears that he could decide on the appointment of judges.
There are also concerns that the planned Criminal Defence System will mean that defence lawyers in publicly-funded cases have no independence from the state, which is bringing the prosecution.
A leading critic of Lord Irvine's plans is likely to be Lord Steyn, a law lord, who said in October the proposals were unacceptable and threatened the independence of judges.
Last week a Lords' select committee, which scrutinises proposed legislation, published a report which criticised the Bill for giving "almost untrammelled" powers to Lord Irvine.
Other objections are likely to focus on the plan to make personal injury cases ineligible for public funding and to make victims find a lawyer who will take their case on a "no-win, no-fee" basis.Reuse content