The Law Society and the Bar Council have offered their backing for amendments to the Police Bill tabled by the Labour Party which are designed to preserve legal privilege.
The move follows a flurry of lobbying from the legal profession.
The proposed amendment, drafted with help from the Law Society, states that surveillance of normal communications between a legal adviser and his or her client would be permitted only if there was evidence that an abuse of legal privilege was taking place.
The Labour party has also agreed to amend the authorisation process so that prior consent for secret surveillance must be obtained from a chief police officer and a commissioner, except in emergencies when the police can seek retrospective approval from the commissioner.
Labour wants there to be at least three commissioners, instead of one as is currently proposed, who will all be senior judges, and a review on the operation of the act in 12 months' time by a senior judge.
Chris Philipsborn, head of the Parliamentary unit at the Law Society, said he was extremely happy with Labour's new stance on the Bill, even if the society did not get all that it wanted. "It is perfectly possible that the Government will be defeated on clause 91, which deals with legal professional privilege."
The amendments will be debated at the Bill's report stage in the House of Lords on 20 January.
The society will hold a briefing on the Police Bill on 21 January at 4pm in committee room 5 at the House of Commons.