The decision to allow over 50 MPs to escape revealing details about their landlords is prompting claims of another expenses cover-up.
Details of letting arrangements requested by Channel 4's Dispatches programme resulted in a number of embarrassing revelations for parliamentarians.
But it has emerged MPs had several weeks' notice of the bid before submitting their information, allowing them to prepare for publication of the details.
Fifty-one MPs were allowed to redact their details altogether, leading to suspicions that some are claiming rent of up to £20,000 on a London flat – and then claiming back the rental cost on a second property, after subletting the first.
A Labour shadow minister named by the Telegraph as Luciana Berger was revealed as renting her flat from an offshore company.
Other MPs whose details were redacted were claimed to be renting off each other – and helping each other to maximise their income in the process.
Speaker John Bercow faces criticism for claiming the redactions were necessary because they might pose a security risk.
"Fundamentally we believe the current system whereby [expenses watchdog] Ipsa pays MPs' rent is deeply flawed, both because it is open to abuse and because it does not represent good value for the taxpayer," Unlock Democracy's director Peter Facey said.
"Introduced in haste at the height of the expenses scandal in 2009, it is high time it was independently reviewed."
Some of the 269 MPs whose landlord details were released proved surprising. Peter Luff, the former defence minister, was revealed as letting a house from Chelsea footballer Frank Lampard.
John Whittingdale, chair of the culture, media and sport committee, has moved out of a second home partly paid for with public money and is now renting it out, while claiming expenses in line with current rules for a rented flat.
A number of peers are letting properties to MPs, as are former MPs who are letting their second homes in London to party colleagues.
Asked by politics.co.uk how David Cameron assessed the rebuilding of public confidence in parliament after the 2009 expenses scandal, the prime minister's spokesperson said this morning: "Clearly it's going to take time."
The row comes as expenses watchdog Ipsa begins a consultation on whether MPs should be expected to commute home after late sittings of parliament – or whether they deserve a flat within a short walking distance of Westminster, a move likely to cost the public purse even more.
"Ultimately, it doesn't matter whether MPs are renting from other MPs, former MPs, party donors or lettings agencies," Facey added.
"They are all private landlords pocketing taxpayers' money, and the public are still the losers."
He called for parliament to acquire secure, furnished properties around central London for MPs to stay in during the week - a system currently used to provide accommodation for service personnel.