Mr Humphries, a former ACT chief minister, said this week a ''creeping conservatism'' was taking hold in the opposition party room and Labor was becoming the natural party of government in the ACT.

He declined to name Liberal MLAs he believed were responsible for imposing their personally-held conservative views and said the party should focus on policy development rather than personality differences.

It was understood Mr Coe, Speaker Vicki Dunne and first term MLA Giulia Jones helped form a conservative block pushing against social reforms in the ACT.

Under Jeremy Hanson, the party last year opposed the introduction of same-sex marriage in the ACT, and Mrs Jones and Mrs Dunne were preparing to tour countries with tough prostitution laws.

Members of the party appeared unimpressed with Mr Humphries' contribution in a Canberra Times opinion piece on Friday.

''It's disappointing that Gary Humphries is continuing to criticise the party of which he was a beneficiary for 25 years as a representative,'' Mr Coe said.

''He should learn from former prime minister [Julia] Gillard about leaving office with dignity.''

Mr Hanson said he would not oppose Prime Minister Tony Abbott and the federal Liberal Party ''simply to score cheap political points''.

''Essentially what Gary is asking us to do is mimic the Greens and the Labor Party in terms of policy and go out there and attack Tony Abbott just for gaining popular support.

''It is sour grapes and he's wrong.

''I will stand up for Canberra and I'll do that at every opportunity.

''But we're not going to do that as megaphone diplomacy through The Canberra Times.''

Mr Humphries restated calls for an open review into the party's unsuccessful 2012 election campaign.

''The reason I went to print is the Liberal Party itself hasn't facilitated a debate about these issues,'' he said.

''It's now 18 months since we lost, and we haven't begun yet the review, which is traditional by every party after it loses an election.

''The chance to discuss where we are heading as a party has been passed over.''

He called on MLAs to ''play the ball and not the man''.

''If they think I am just a lone voice, let them ask other party members what they think in the form of an open review and let's see how isolated or embittered that voice might be,'' he said.

The opinion piece said a ''malaise'' was afflicting the Canberra Liberals and the party should be more vocal in opposing public sector job losses under the Abbott government.

Mr Humphries said NSW Premier Barry O'Farrell had expressed effective opposition to conservative views on same-sex marriage and proposed reforms to the Racial Discrimination Act.

He had done so without losing favour of some Liberal voters, he said.