The Association of Personal Injury Lawyers has introduced a compulsory code of conduct after a heated debate about the public image of its 3,000 members.
The code was backed at Apil's conference in Manchester on Friday, when president Caroline Harmer confirmed that any lawyer who does not subscribe to the code will be barred from the organisation.
Apil is one of the first lawyers' groups to have taken a regulatory role, and its move follows widespread concern within the group that the Law Society's rules are too liberal.
Harmer said there was little or no resistance from members to its introduction. However, the press was barred from a final vote on the subject.
Harmer said Apil's code was "complementary" to existing Law Society regulations. It will outlaw practices such as cold calling accident victims, sending out unsolicited mail and offering payment for referrals.
During a debate on the code, Kerry Underwood, senior partner of St Albans firm Underwood, defended the profession. He said: "I do not see a contradiction between being a caring professional and an ambulance chaser in the broadest sense."