Yesterday, in an op-ed for Fairfax, former Howard government minister Amanda Vanstone took aim at the Abbott government over its proposal to hand the Immigration Minister the power to strip Australians of their citizenship.

Vanstone has been a consistent critic of the over-the-top nature of our response to terrorism, even when she was a minister, famously mocking the imposition of plastic cutlery on aircraft.

But her criticisms of the Abbott government go much deeper, to the very ideology that motivates Abbott:

“One of the main reasons I am a Liberal is the commitment to individual rights. So you can imagine my profound disappointment, bordering on despair, when I see some on ‘my team’ thinking it is OK for a minister alone to take away a citizen’s rights — indeed, take away citizenship — in the blink of an eye. No appeal, no judicial process, just a ministerial decision. What were they thinking?”

With those words, Vanstone nailed the gulf between the classic liberal position, which is that governments should not have unfettered authority to harm the individual and that executive power must be checked by other arms of government, and the position of the Abbott government, which is that any criticism or questioning of unfettered powers is tantamount to supporting terrorism.

Ironically, Human Rights Commission president Gillian Triggs is being attacked by a Liberal government while articulating exactly the same concerns about unfettered executive power and the need for checks and balances.

Nor is this a concern shared only by small-L Liberals like Vanstone or Malcolm Turnbull. The government’s proposal to strip anyone deemed somehow connected to terrorism of their citizenship attracted concern from ministers such as Barnaby Joyce and Kevin Andrews as well.

To the extent that the Liberal Party is a mix of both conservatives and liberals, Tony Abbott’s abandonment of a key tenet of liberalism marks a significant milestone. In one of the most crucial ways, Abbott’s Liberal party is no longer worthy of the name.

No wonder figures like Vanstone despair.