Foreign Minister Julie Bishop has confirmed that her Chief of Staff Murray Hansen was at the meeting of Liberal MPs on September 13, plotting Tony Abbott’s coup, according to ABC.

But the deputy Liberal leader thought Hansen was just “going for drinks” at NSW MP Peter Hendy’s house.

“I did not know who would be attending the meeting,” Ms. Bishop told the media on Thursday. “When I learned who was there on the Monday morning and when cabinet ministers came to see me I made the first opportunity available to see the prime minister.”

“I met him within five minutes of his attendance here in Parliament House,” she added.

The revelation about Mr. Hansen’s participation in the meeting is contained in a new book, “Battleground, by political author and academic Wayne Errington and The Australian columnist Peter van Onselen.

Ms. Bishop said it was up to all members of the leadership team, to keep their ears to the ground and warn the prime minister about any looming problems.

“Its the job of every member of the leadership team: the leader of the senate, the leader of the house, the deputy prime minister, the deputy leader, the prime minister to know what the backbench is thinking and that’s precisely what I was doing,” she said.

Former cabinet minister Eric Abetz, who vociferously backed Mr. Abbott during the leadership crisis, said the revelation was “disappointing” and MPs were “entitled to know exactly what was going on”.

“When I was a minister I would have never countenanced my chief of staff going to such a meeting without my approval,” Senator Abetz told Sky News.

“One would imagine that if there were such a meeting there might have been an obligation to, as a loyal deputy, to report that to the leader at the time.”

“We need to get to the bottom of this,” another Abbott supporter Cory Bernardi said to the media.

Mr. Malcolm Turnbull replaced Tony Abbott as prime minister in a Liberal party room ballot on September 13.