Taxpayers will pay up to $1 billion to fund the retirements of politicians under an axed parliamentary pension scheme, and the cost of the scheme will blow out by another 10 per cent by 2020 to $50 million a year.

A wave of pre-election resignations on both sides of politics this year will see the public foot the bill for their post-politics lives, with the total amount expected to reach a peak of $59 million in 2033.

Retiring Coalition ministers Christopher Pyne, Julie Bishop and Nigel Scullion are set to receive between $188,000 and $220,000 a year for the rest of their life. Steve Ciobo, 44, will be eligible for the same payment after he turns 55.

Christopher Pyne (left) speaks to Steve Ciobo in the House of Representatives. Credit:Dominic Lorrimer

The scheme was axed in 2004 because it was seen as too generous, but it continues to apply to those elected before then.