Government 'will reform lobbying' after peers accused of breaking rules
The government says it could change the rules on lobbying within the next year, after three peers were accused of agreeing to carry out Parliamentary work for payment.
Minister Francis Maude said the coalition was working out detail but called such a timetable "possible".
Labour's Douglas Alexander said he was "angry" over the Sunday Times' claims.
Ulster Unionist peer Lord Laird, Labour's Lord Mackenzie of Framwellgate and Lord Cunningham deny wrongdoing.
Lord Laird has resigned his party's whip pending the outcome of a review of his behaviour, the party said - and Labour said Lord Cunningham and Lord Mackenzie had been suspended from the party pending an investigation.
Undercover reporters filmed the men appearing to offer to help a fake solar energy company.
The story comes two days after Conservative MP Patrick Mercer resigned the Tory whip on Friday amid claims he broke lobbying rules. He also denies any wrongdoing.'Deeper questions'
Before becoming prime minister, David Cameron described lobbying - advocacy to politicians on behalf of organisations such as business, charities and trade unions - as the "next big scandal waiting to happen".
The coalition government promised to set up a statutory register of lobbyists and to ensure "greater transparency".
Critics say this has taken too long to happen, but Mr Maude, the Cabinet Office minister, told BBC One's Sunday Politics: "We are going to introduce the statutory register of lobbyists. That's a commitment.
"There's a certain amount of debate about what it should cover."
The register of lobbyists would specify which are legitimate organisations, after they have been assessed according to guidelines on suitability.
But no plans were mentioned in last month's Queen's Speech, which set out the government's legislative programme for the next year.
Mr Maude said: "It won't necessarily be in the next Queen's Speech, because it's perfectly possible we will legislate for it in the next session...
"The Queen's Speech is important, but it's not necessarily the be-all and end-all."'Committed'
Energy and climate change minister and Conservative MP Greg Barker echoed Mr Maude, saying: "We said in the coalition agreement that we would bring forward a statutory register for lobbyists and people who make politics their livelihood and that is what we will do.
"We've already published a Green Paper and work is under way in the Cabinet Office and I'm sure that these latest, very depressing, allegations will spur on that work. But we are absolutely committed to bringing that forward and bring it forward we will."
Concerns have been raised that a register could be ineffective if only specific lobbying companies - rather than organisations who choose to lobby by themselves without extra help - are included.
For Labour, shadow foreign secretary Douglas Alexander told BBC One's Andrew Marr Show: "I am angry as a citizen of the United Kingdom that this seems to be happening in Parliament and I am angry as a politician that the good name of the endeavour of politics - trying to find shared solutions to shared problems - is once again being smeared by what appears to be conduct that literally cannot be defended."
He added that "due process" had to be followed over each of the allegations, but said Labour wanted to see cross-party talks immediately with the government in relation to lobbying, "and how we can get it on a proper footing".
He added: "We have got to ask deeper issues in relation to the House of Lords... in terms of making sure that people can have confidence as to the motive of the legislators, whether in the Commons or in the Lords."
The House of Lords code of conduct says peers cannot engage in "paid advocacy" - using their access to Parliament to make a profit.
Former chairman of the Committee on Standards in Public Life Sir Alistair Graham said the latest cases illustrated the "vulnerability of our democratic system to people who want to use money to gain access to influence our parliamentary processes".
The House of Lords was "ripe for reform", he told Sunday Politics.
On Saturday, the BBC's Panorama programme released footage - secretly filmed - of Mr Mercer appearing to offer a Commons security pass to a fake Fijian firm that paid him £4,000 to ask parliamentary questions.
Mr Mercer said he had taken the money for consultancy work outside Parliament, that he was taking legal advice and that he had referred himself to Parliament's standards commissioner.
On Thursday, Panorama will air allegations from its joint investigation with the Daily Telegraph.
Panorama will be shown on BBC One at 21:00 BST on Thursday.