Plans to give voters the ability to recall MPs are not being introduced to give politics an "aggressive tool", Nick Clegg has told MPs.
The deputy prime minister and his Conservative minister Mark Harper downplayed the impact the reform will have in an evidence session in front of MPs.
Under the coalition's proposals a by-election could be triggered if ten per cent of voters in an MP's constituency sign a petition demanding the vote.
The petition would only be permitted if the MP is jailed for under 12 months or if the Commons decides "serious wrongdoing" has taken place, however.
"I make no apology for the fact that what we're trying to do is set some rules of the game," Mr Clegg told MPs on the political and constitutional reform committee.
"We have to explain to people this is a balance, between giving people the right to recall their MP, but it's not a free-for-all."
Radical reformers like Conservative MPs Douglas Carswell and Zac Goldsmith have expressed frustration that the change, promised by all three parties in their 2010 general election manifestos, does not go further.
Committee chair Graham Allen suggested that, now the 2009 expenses scandal has begun to fade into the past, the resolve of MPs to change the current system has diminished.
"I get a sense from colleagues that to some extent this is fighting yesterday's battle," he said.
"There was an aura about what MPs were like and should do, and two years later there's a slightly different sense."
Mr Clegg replied: "Before we all retreat from the commitments we made before the last general election... there is still a need for a backstop sanction - rather than an aggressive tool that would be overused for political purposes."
Mr Harper said it was important that the government was "very clear with voters" about what the limited reform means.
"The danger is you oversell it and disappoint people," he acknowledged.
Deputy prime minister Mr Clegg said the fear that MPs deciding on whether a by-election should take place in a "you scratch my back, I'll scratch yours" arrangement was "legitimate".
But he insisted the commissioner for standards and the committee on standards and privileges had not been "slouches" in "making it very difficult for the House to somehow brush things under the carpet".
"We've got these belt and braces arrangements in place which have strengthened significantly in recent years," Mr Clegg added.
The recall of MPs draft bill was published by the Cabinet Office in December 2011.