Ex-PM Kevin Rudd will face the home insulation royal commission this week amid revelations his minister Peter Garrett warned him about safety risks.

Former prime minister Kevin Rudd is fronting a royal commission this week to answer questions about Labor’s home insulation debacle and whether he heeded warnings from a cabinet colleague.

The environment minister in charge of the disaster, Peter Garrett, is also being grilled about his role in the $2.8 billion stimulus scheme linked to four deaths and 224 house fires.

While the former Midnight Oil frontman was demoted in 2010, it has since emerged that he wrote a series of letters to Mr Rudd warning of safety risks in the scheme.

It’s unclear whether the letters will be shown at the inquiry as commonwealth lawyers may seek to have them withheld.

The letters have been provided by the coalition government, which threatened, in opposition, to give them to a royal commission.

Labor says the $20 million inquiry is a political witch-hunt, but the government argues the public deserves to know how four men died.

Queenslanders Matthew Fuller, Rueben Barnes and Mitchell Sweeney, and Marcus Wilson from NSW, lost their lives installing insulation.

Their relatives have waited more than four years for Mr Rudd and Mr Garrett to publicly detail their roles in the disaster.

The inquiry has heard from 49 witnesses so far, but few have admitted personal responsibility.

Public servants have told the royal commission of being put under extreme pressure to roll out the scheme by July 1, 2009.

Two senior bureaucrats said they were given just two days to assess and cost it, while another said Mr Rudd’s “horrendous” timeline denied their department adequate time to consider safety risks.

A state coroner has already found the scheme’s rushed rollout was a significant factor in the three Queensland deaths.

Mr Garrett will appear at the commission on Tuesday and Mr Rudd will follow on Wednesday.

Former senator Mark Arbib, who co-ordinated Labor’s stimulus programs, will give evidence on Monday, while former Labor frontbencher Greg Combet, who oversaw the scheme’s closure, will appear on Friday.

Mr Fuller’s father, Kevin, and Mr Barnes’s sister, Sunny, are expected to address the inquiry on Thursday.