Dozens of former MPs - including Westminster abstentionist Martin McGuinness - have been granted privileged access to Parliament since the general election.
Some 381 former Members are in possession of passes that allow them to roam the Westminster estate and use the subsidised facilities.
They include ex-Labour Home Secretary Jack Straw and Tory Sir Malcolm Rifkind - both being probed by the Commons standards watchdog after being caught up in a lobbying sting. They deny wrongdoing.
Sinn Fein's Mr McGuinness, disgraced former Cabinet ministers Chris Huhne and Jonathan Aitken, and many Liberal Democrats who lost their seats on May 7 are also on the list.
Stormont's Deputy First Minister, who never took up his Commons seat over the oath to the Queen, has decided he still wants to be able to visit the estate despite stepping down in Mid-Ulster two years ago.
MPs who have served at least one full parliamentary term are eligible to apply for the 'Category X' passes.
The scheme is intended to smooth the process of returning to civilian life.