Nick Clegg has called for major reform to the House of Lords in the wake of allegations of expense abuse against a peer who has already been jailed once over his claims.
"A big part of the problem is that, right now, a place in the House of Lords amounts to a job for life," the Deputy Prime Minister wrote in the Daily Mirror. "Unelected peers don't need to seek voters' consent.
"Our Parliament should be the envy of the world: a modern, transparent and democratic institution. Instead it's a relic from the 17th century."
Mr Clegg accepted that the Lib Dems had failed in their drive to secure an elected House of Lords during this Parliament.
But he added: "The British people deserve better. This latest scandal must re-energise our call for change. At the next election, my party's manifesto will once again contain a clear commitment to an elected second chamber."
A peer who has defended regularly "clocking in" to claim a £300 daily allowance said he found The Daily Mirror's report on him "very offensive" and that he was a "hardworking" member of the House of Lords.
The leader of the Lords said he felt "dismay" over reports that a peer who was jailed for expenses fraud had regularly "clocked in" for a brief period of time to claim a £300 daily attendance allowance.
Lord Hill of Oareford told peers: "[I feel] dismay about the behaviour and dismay about the shadow it casts over the whole House".
In a short statement, he added that steps would be taken to "deal with the small number of members whose behaviour falls below the standards we rightly expect".
Lord Hill of Oareford's comment came after Lord Hanningfield - who served nine weeks of a nine-month sentence in 2011 for falsely claiming £28,000 in parliamentary expenses - said it was normal practice and claimed as many as 50 others did the same.
There is no suggestion that the former Conservative broke any rules.
Labour MP John Mann is expected to formally request an investigation into Lord Hanningfield after it emerged that he allegedly "clocked in" to claim a £300 daily attendance allowance despite spending less than 40 minutes inside the House of Lords on 11 occassions in July.
There is no suggestion that the former Conservative broke any rules, but he faced calls from the Labour MP for him to be investigated by parliamentary authorities over the practice.
Mr Mann said: "There needs to be a full investigation into how he has been allowed to get away with it. We need to give the House of Lords a proper and transparent spring-cleaning."
David Cameron's official spokesman said he had not spoken to the Prime Minister about Lord Hanningfield's alleged "clocking in" claims but told reporters: "I understand the concerns that have been raised."
The House of Lords Commissioner for Standards - who is is responsible for investigating alleged breaches of the peers' code of conduct including on the use of expenses - has not yet received any complaint about Lord Hanningfield, a spokesman said.
Kevin Maguire, associate editor of the Daily Mirror, believes that although Lord Hanningfield did not break any rules when he allegedly "clocked in" to claim a daily attendance allowance, the "rules are wrong".
He told ITV's Daybreak: "He may not be breaking any rules but if that's the case then the rules are wrong because I don't know anybody else who could just turn up, nod to an attendant who ticks your name and then you can leave with a £300 tax-free allowance."