THE federal opposition is yet to formulate a position on the proposed internet filter despite Labor flagging its intention to introduce the measure before the last election.

The failure of Coalition leader Tony Abbott or his communications spokesman Tony Smith to indicate whether they would support the bill reflects divisions within the party about the government's plan to block access to internet sites banned under Australia's classification rules.

The Greens are opposed to the filter, giving the Liberals the crucial votes in the Senate that determine the success of Communications Minister Stephen Conroy's plan, which has attracted criticism from Google, the United States and others in the internet industry.

On Monday night, when asked about the filter on the ABC's Q&A program, Mr Abbott explained key arguments for and against the proposal but did not articulate a definitive position.

''I want to see protections in place,'' the Opposition Leader said. ''I don't want to see our kids exposed to really terrible stuff on the internet. On the other hand, I don't want to see the internet destroyed by a filtering system that won't work, so I guess for me it's a factual issue.