The Federal Liberal Party has announced new rules to make it harder to knife a sitting prime minister.

Key points: MPs were called to an after-hours meeting to discuss the motion

MPs were called to an after-hours meeting to discuss the motion Had the changes been in place earlier, Malcolm Turnbull would still be prime minister

Had the changes been in place earlier, Malcolm Turnbull would still be prime minister The motion reflects similar changes made by Labor after its leadership turmoil

Prime Minister Scott Morrison introduced a new threshold to trigger a Liberal leadership change in government, requiring two-thirds of the partyroom vote to trigger a spill motion.

The Liberal Party previously had no set method and no partyroom constitution dictating this.

Mr Morrison said the changes, which were drafted with feedback from former prime ministers John Howard and Tony Abbott, would only apply to leaders who win an election.

If these changes had been in place before the August leadership spill, Malcolm Turnbull would still be prime minister.

The changes wouldn't apply to the deputy leader position.

Mr Morrison said the change to party rules reflects an acknowledgement that the party's "own conduct of this period of time needs to be changed".

"What this is doing is putting the power of the decision of who elects prime ministers back in the hands of the Australian people," Mr Morrison said.

Scott Morrison would not have replaced Malcolm Turnbull as leader if the changes were made earlier. ( ABC News: Matt Roberts )

"This is a practical demonstration to the Australian people that mean it, that we are fair dinkum about it, and that's why the party has made this change."

Deputy Liberal leader Josh Frydenberg said leadership spills have "diminished the reputation in the eyes of the public" at that change was needed.

"The Liberal Party has listened to the Australian people and the Liberal Parliamentary Party has responded tonight," Mr Frydenberg said.

"The prime minister we take to the election will be our Liberal prime minister after the election.

"The Prime Minister received very strong support from colleagues tonight and the issue was discussed fully — there were a number of constructive contributions.

"We have agreed on a way ahead and our focus is on the Australian people."

Former prime minister Tony Abbott gave feedback for the changes. ( ABC News: Matt Roberts )

Mr Morrison said the leadership team asked the party whips to consider making changes debated tonight.

The special partyroom meeting, which surprised many Liberal MPs who were at social events, ran for more than an hour.

The changes are similar to those previously announced by the Labor Party to prevent leadership changes.

To change a Labor leader, a minimum of 60 per cent of the Labor caucus must vote to remove a leader if the party is in Opposition.

To remove a Labor prime minister, 75 per cent of the caucus must vote for change.