The association’s director general Francis Ingham was reacting to the passage of the bill through the Lords last night.
The bill, which will introduce a statutory register of lobbyists, only requires royal assent before it becomes law.
Ingham said: "Professional, ethical lobbyists have nothing to fear from transparency. In fact, for the past two decades, our industry has embraced higher levels of disclosure on lobbying activities than the Government now proposes.
"We welcome the fact that the Government has conceded in several key areas, most notably ensuring that the register will detail where lobbyists do or do not subscribe to existing industry codes of conduct.
"Nonetheless this is not an Act that will stand the test of time. By excluding in-house teams the Government guarantees that its successor will have to revisit this issue. And the PRCA will help its successor to do just that."