Prime Minister Tony Abbott faced a "cavalcade of complaints" in Tuesday's Liberal party room meeting, including repeated questioning from WA MP Don Randall about why former chief government whip Philip Ruddock was axed.

Mr Abbott was also confronted by South Australian MPs Andrew Southcott and Rowan Ramsey about the future submarine project, with Mr Ramsey warning the Prime Minister he would be breaking an election promise "if the hulls aren't welded" in South Australia.

And Liberal MPs Craig Laundy and Andrew Laming raised concerns about the attack on the Human Rights Commission President Gillian Triggs and the issue of children in detention.

Treasurer Joe Hockey also briefed MPs that a discussion paper on foreign investment would be released shortly for public consultation.