The Labour Party says it has withdrawn an amendment from the Lobbying Disclosure Bill that would have exempted unions from the disclosure regime.
The bill, in the name of Green MP Holly Walker, is being considered by the Government Administration Select Committee.
It is aimed at establishing a disclosure regime for anyone who seeks to influence MPs, their staff or public servants. It would establish a statutory register of lobbyists, and lay out a code of conduct.
Lobbyists would have to disclose the date of their meetings, who was present and the subjects discussed.
Labour MP Charles Chauvel had intended to put forward amendments excluding union and other non-government organisations.
He now says he'll drop the provision relating to unions, but will keep his other amendments.
The Council of Trade Unions has said it is happy to be part of the scheme, as long as it's fair to all parties.