A group of retired politicians trying to claw bigger pensions and more free travel from the taxpayer will get their day in court next month.

The High Court has agreed to hear the challenge by four former federal MPs – Labor's Barry Cunningham, Tony Lamb and Barry Cohen, and Liberal John Moore – seeking a big boost to their entitlements.

Former Defence Minister John Moore is one of four former MPs who launched a High Court bid for better taxpayer-funded retirement benefits.

While the federal government has sought to have the case thrown out, the court's full bench will convene to hear the case on June 16, putting politicians' perks back in the spotlight just two weeks before the July 2 election.

If the case is successful it could benefit up to 350 former politicians and 100 spouses, adding millions of dollars to the $40 million pension bill taxpayers already pick up every year. Most MPs who entered Parliament before 2004 are entitled to generous pensions under a defined benefits scheme.