Peter Costello's to blame for the leadership crisis tearing the party apart

The federal Liberal Party is in an unprecedented crisis.

At no time in the 65-year history of the Liberals or any of their predecessors has a leader been confronted with such a walkout of his own front bench as occurred last week with Malcolm Turnbull.

Never before has a Liberal leader gone so public to attack members of his own party rather than his Labor opponents. And never has a Liberal leader sounded so much like a Labor ideologue staking his claim by appealing to a principle of policy, in this case the emissions trading scheme, rather than the need to secure a compromised policy outcome based on political and, most importantly, practical considerations of implementation.

First, the wrong people have been appointed to the Liberal leadership too early in their careers. When that happens in any political party the results are disastrous. When it happens in a leader-centric party such as the Liberals it is catastrophic. We saw this when John Hewson became leader after the 1990 election. His ideologically based Fightback program resulted in the Liberals losing the "unlosable" 1993 federal election.

Second, the Liberal Party is on the verge of selecting its third federal parliamentary leader in less than two years because the person who should have taken the baton from John Howard after the 2007 election defeat, Peter Costello, declined to do so.

Howard had groomed a range of younger members into cabinet who had future leadership potential. Brendan Nelson had defence; Tony Abbott, health; and Joe Hockey, industrial relations. Howard appreciated these individuals might be ready for leadership in a couple of elections hence. They needed political maturing.

The immediate successor was to be Costello. He was firmly anointed as such by Howard on election night 2007.

Costello, as deputy leader and treasurer, was not just the heir apparent by default but one who was young, experienced and a proven performer. Moreover, in private comment and public outburst, Costello had indicated he had wanted the leadership. Or was it only the prime ministership?

Importantly, Howard observed on election night that "the future of our party is very tied up with Peter Costello". How prophetic this comment was because it has been Costello's behaviour since then that has been the source of the Liberals' problems.

Costello's unwillingness to take up the leadership caused problems as it resulted in the initial move to Nelson as leader.

Costello's ambivalent attitude to whether he would stay in parliament caused further leadership instability for Nelson.

It also possibly tempted Malcolm Turnbull to destabilise Nelson and take on the leadership earlier than expected.