The majority of federal politicians who have announced their retirement this year will be paid annual pensions of at least $118,000 - and in some cases much more - adding more than $2 million to the annual bill.

Of the 22 MPs and senators who have already announced they will not re-contest the upcoming election, 16 are believed to be eligible for the controversial Parliamentary Contributory Superannuation Scheme.

Former ministers Warren Truss and Ian Macfarlane are among 16 retiring MPs who will benefit from a generous six-figure parliamentary pension. Credit:Andrew Meares

Only available to politicians elected before 2004, the defined benefits scheme already costs taxpayers more than $40 million a year.

Eight Coalition and eight Labor MPs are set to qualify this time and most will be paid a minimum of $118,125 – or 75 per cent of a current MPs base salary for superannuation purposes of $157,500.