The UK Public Affairs Council will launch its public register of lobbyists on March 1 at the House of Commons.
The council was created last year by the CIPR, PRCA and the Association of Professional Political Consultants.
The new register will combine the quaterly registers operated by the APPC and PRCA and will include CIPR lobbyists.
However as PR Week went to press, only 245 CIPR members had registered for the new scheme.
Lobbyists will receive a voluntary register will stave off demands for heavy-handed legislation, but some MPs are sceptical.
Earlier this month, Labour back-bencher Michael Meacher told the Commons: "Parliament should require a public register."