Patricia Hewitt, Stephen Byers and Geoff Hoon were caught in an undercover sting boasting that they had changed government policy and secured preferential access to ministers for private companies.
Channel 4's Dispatches worked with The Sunday Times on the investigation which recorded Byers describing himself as a ‘sort of cab for hire' with rates of up to £5,000 a day.
Labour has already responded by pledging to enforce a compulsory register of lobbying, someting the party claims was planned for its forthcoming election manifesto.
But lobbyists said the prime minister should be directing his anger at the disgraced ex-ministers, not the industry.
Hanover Communications MD Charles Lewington said: ‘Gordon Brown needs to put a lot of distance between himself and the three quite quickly. Withdrawing the whip would be a start. This is definitely a case of MPs trying to feather nests before they go, as they did in the 1990s.'
‘They all remember how hard it is to get a job as an ex-MP even in good times. Backing a statutory register for lobbyist is deliberately missing the point as it alone would do nothing to stop MPs taking outside interests.
Lewington, a former Conservative Party comms chief, added: ‘As for reputation, Lord Ashcroft, Unite, expenses and now this, is contributing to a 'plague on all your houses' feeling, but also contributes to the sense that it is time for a change and we can't go on like this.'
DLA Piper UK head of media and director, global Government relations, Eben Black said: ‘It is not good for the image of Parliament that MPs can apparently be so easily tricked into saying stupid things.'
Weber Shandwick chairman, corporate comms and public affairs, Jon McLeod said the latest scandal made statutory regulation of lobbying ‘inevitable'.
He added: ‘Yet again it is the fumbling attempts of Parliamentarians to be lobbyists that have cast a shadow over the professional practice of the industry. Statutory regulation of lobbying is both right and inevitable.'
The ‘cash for access' story has made the front page of The Independent, The Times, The Daily Telegraph and The Guardian this morning. The Independent ran with the headline: ‘Ministers furious at new lobbying ‘scandal'.'