- Publication of MPs expenses has been paused indefinitely, with a planned release in May now unlikely.
- Details of claims were halted after the murder of Sir David Amess in October 2021.
- The security review, launched after Amess's murder, was expected to conclude in March.
The details of how MPs spend taxpayers' money to pay for their offices and second homes will continue to go unpublished beyond May, after not being published since September 2021.
The Independent Parliamentary Standards Authority (IPSA), which is responsible for verifying and publishing expense claims from MPs, was due to publish details of claims in May, the first time it had published expenses details in nearly eight months.
IPSA previously published claims every two months, but paused publication following the murder of Sir David Amess. The expenses watchdog also removed the detail of already published expenses claims going back to 2010.
IPSA said it would publish expenses claims once a security review, launched after Amess's murder, had concluded, and suggested this might come by the new tax year starting in April 2022.
But minutes of an IPSA board meeting on March 2 reveal that the review, run by Parliament's Members Security Support Services, had not yet concluded.
IPSA's board agreed to "await the results of MSSS' security review before resuming bimonthly publication and deciding in what form this might proceed." At the time, the board believed the review might conclude at the end of March.
But a Parliamentary source, given anonymity to speak frankly about security matters, told Insider that there were "are on-going changes to MPs' security arrangements". They said that "MPs will be updated in the coming weeks".
An IPSA spokesperson told Insider they had not yet heard a publication date for the security review.
Campaigners say the data should be released as soon as possible.
Rose Whiffen, research officer at Transparency International UK, told Insider: "While the safety and security of our elected officials is of paramount importance, opacity over MPs' expenses should not become the status quo.
"Transparency is vital to guard against the misuse of public funds by shining a light on those who abuse the system, as well as deterring others from doing the same.
"History illustrates vividly the need for openness around expenses, so this data should be released as soon as possible."
Some MPs have criticised the publication scheme, saying it is equivalent "to bullying".
Insider has reported a number of stories on MPs expenses using data released by IPSA, including a series of stories on how Karl McCartney, Conservative MP for Lincoln, claimed in expenses for more than £30,000 of taxpayers' money for work he handed to a donor's firm.