As a vote on same-sex marriage nears in the Australian Parliament, the public believes members should vote according to their principles, not party direction.

In a survey conducted by the Sydney Morning Herald with Nielsen last week, 81 percent out of 1,400 voters polled had indicated that Senators and members of the House of Representatives should have a free conscience vote.

The same poll indicates that many voters have shifted their allegiance in recent months.

The new data points to dwindling support for gay marriage, a stand that directly contradicts the policy adopted by the ruling Australian Labor Party during its recently held national conference.

Two points, however, prevailed at the ALP summit - most Labor members supported gay unions but as a compromise for those who opposed, chief among them Prime Minister Julia Gillard, the party also allowed Labor MPs to exercise a conscience vote.

According to SMH, a private members bill would be filed by Labor MP Stephen Jones once Parliament session resumes next year with the likelihood of being quashed eventually as not too many ALP votes support the initiative.

Also, the bill could not expect any form of support from the Coalition as Opposition Leader Tony Abbott has reiterated Monday that he will not sanction a conscience vote among members of his bloc.

Abbot reminded his colleagues that the party had made a pact with voters regarding the issue during the last national elections, pressing on them that killing the legislation is the core of the Coalition agenda.

Despite suggestions coming from senior Liberal member Malcolm Turnbull that conscience voting must be considered by the opposition, Abbott warned that it directly contradicts the party's philosophy.

The pledge that the Coalition had made with the electorate last year, Abbott stressed, must be "an extremely powerful factor with every single member of my Coalition."

He conceded though that members of the Coalition may opt to cross the party line and they will remain with the party but shadow ministers who do so, Abbott pointed out, must relinquish their posts.