The main parties have united to increase secrecy about the running of Federal Parliament, with a new law set to prevent revelations about some of the perks enjoyed by MPs.

Three departments - with a total budget of $170 million - that oversee Parliament will gain a blanket exemption from freedom of information laws.

"Interim measure": Anthony Albanese. Credit:Alex Ellinghausen

The Gillard government claimed an ''anomaly'' had been found last year when Fairfax Media successfully obtained information about the travel, catering and clothing purchases of former speaker Peter Slipper.

But even the departments involved admitted they did not need a blanket exemption. And the law has been rushed through the House of Representatives even though an independent review on the issue is expected to be released soon.