lobbyist

One who frequents the lobby or the precincts of a legislature or other deliberative assembly, with the view of influencing the votes of members.

A member of the lobby; a person who solicits members of a legislature for the purpose of influencing legislation.

A person remunerated to persuade (to lobby) politicians to vote in a certain way or otherwise use their office to effect a desired result.

someone who is employed to persuade legislators to vote for legislation that favors the lobbyist’s employer