''Della's [John Della Bosca's] pet crocodile'' and ''Eddie Obeid's left testicle'' were two of the nicknames used by Labor colleagues to refer to the former primary industries minister Ian Macdonald's treachery towards the Left, a senior factional figure, Luke Foley, told the corruption watchdog yesterday.

Mr Foley, a former Left assistant secretary of the NSW Labor Party and now a member of the NSW Upper House, was giving evidence to the Independent Commission Against Corruption about his attempts in 2006 to strip Mr Macdonald of his preselection for the NSW Upper House.

Evidence on cabinet protocols: former premier Nathan Rees. Credit:Ben Rushton

The commission is investigating Mr Macdonald's decision to grant a coal exploration licence to a group of investors, including former mining union boss John Maitland, at Doyles Creek in the Hunter, in 2008 without tender and against departmental advice.

Mr Foley said that in 2006 he had received a ''chorus of complaints'' about Mr Macdonald's conduct and there were growing doubts about his loyalty to the Left.