MPs claimed £3.6m to rent offices from political parties
The expenses watchdog has published details of the landlords of MPs' offices for the first time - showing £3.6m was paid to political parties.
The Independent Parliamentary Standards Authority (Ipsa) says there were 244 offices leased from a political party between May 2010 and April 2013.
There were 477 leases which were not with political parties.
There are no rules to stop MPs renting from a political party, but Ipsa says it is to review the rules.
The current rules include checks that those who rent from parties do so at commercial rates to prevent an extra taxpayer "subsidy" to that party.
The figures released show the average rent paid to a political party is £14,886, compared with £14,156 for those renting from other landlords.
The chairman of Ipsa, Sir Ian Kennedy, issued a statement saying: "Many MPs hire offices for their staff to work in and in which to meet constituents. It is right that we support them to do so. But we also think it is in the public interest to publish where that money goes.
"Transparency is crucial to re-building trust in politics, and making sure public debate is built on a foundation of facts.
"We are reviewing the most appropriate ways to provide accommodation for MPs' offices, and will report back in the Spring. We established the current rules after listening carefully to the public. I think it is only right that we ask the public what they think if we decide those rules need amendment.
"Our rules allow MPs to rent from a political party - but we require an extra assurance from MPs if they do so: an independent valuation that the lease represents the market rate. We are confident that this measure means taxpayers have received value for money from these leases.
"The analysis we are releasing today shows that a third of all leases are with political parties.
"As part of a broad review of accommodation support, Ipsa will consider whether, even if the individual leases are appropriate, the cumulative effect means we need to reconsider this aspect of the rules."
MPs who have claimed expenses to rent office space from their political party during this parliament include Deputy Prime Minister Nick Clegg, his Liberal Democrat cabinet colleague Danny Alexander and former party leaders Charles Kennedy and Sir Menzies Campbell.
Among the Conservatives listed are Education Secretary Michael Gove, Justice Secretary Chris Grayling, Health Secretary Jeremy Hunt, Work and Pensions Secretary Iain Duncan Smith and International Development Secretary Justine Greening.
For Labour, shadow justice secretary Sadiq Khan and shadow consumer minister Stella Creasy also feature, as does former Foreign Secretary David Miliband.
However, neither David Cameron nor Labour leader Ed Miliband rent from their parties.
Jonathan Isaby, political director of the TaxPayers' Alliance, said: "It's one thing if a local political party offers their MP and staff free use of a desk or an office, but quite another for it to be sending taxpayers an annual invoice for thousands of pounds."
He added: "It's effectively a back-door subsidy to political parties that is exploiting an allowance meant to assist MPs in their work serving their constituents, not boost the coffers of their re-election campaign."