The Government will bring forward a bill to introduce a statutory register of political lobbyists before Parliament breaks for the summer, Downing Street announced today.
The announcement follows allegations that a Conservative MP, two Labour lords and an Ulster Unionist peer were prepared to exercise political influence in exchange for cash from undercover reporters posing as lobbyists.
The legislation, which is set to be published before July 18, will also include measures to curb trade union election spending - a move which has already sparked political debate.
The measures could make it harder for trade unions to take strike action or support candidates in election campaigns.
A Labour Party source denounced the package as a "shabby and panicked" response to the recent rash of negative headlines, while the TUC accused the Government of "cynically trying to exploit a political sleaze scandal to crack down on unions".
There were also signs of confusion within the Coalition as deputy leader of the Commons Tom Brake - the Liberal Democrat minister leading for the party on lobbying - suggested that the provisions affecting unions had been announced "prematurely" and were not yet fully fleshed out.
This morning the Deputy Prime Minister Nick Clegg made a public promise that the statutory register would become law before the end of the Parliament in 2015.
It was also announced that the House of Lords standards commissioner has begun investigating the three peers caught up in the latest scandal.
Ex-cabinet minister Lord Cunningham and Lord Mackenzie of Framwellgate, who have both been suspended by Labour, and Lord Laird, who has resigned from the Ulster Unionists, have all denied any wrongdoing.
Speaker John Bercow has reportedly ordered the suspension of more than 80 House of Commons passes amid concerns over lobbying.