Nearly four-fifths of the public want to see the Green party represented in next year’s televised leaders’ debates before the election, according to an ICM opinion poll. The poll is likely to put more pressure on broadcasters to lift their objections to including the Greens.

At present, the broadcasters have said Labour, the Conservatives, Ukip and the Liberal Democrats will all be involved in at least one of the three planned debates

The poll, which was conducted between 12 and 16 December, shows 79% support for the involvement of the Green party, a support reflected pretty evenly across age, gender and region. Even Conservative voters support the Greens’ involvement by a 62%-to-36% margin. Ukip identifiers support the Greens’ participation by 70% to 26%, Liberal Democrats by 86% to 14% and Labour supporters by 82% to 14%.

The question put to poll respondents read: “You may have seen or heard that ITV has announced proposals for a televised leaders’ debate in the runup to the 2015 general election which is likely to be held in May next year. ITV currently propose to invite the leaders of the Conservative party, Labour, the Liberal Democrats and Ukip to participate, but not the leader of the Green party. Do you think that the leader of the Green party should or should not also be invited to join in the ITV leaders’ debate?”

The Greens say it was verified by ICM to ensure there was no bias. ITN was asked to participate in the framing of the question, but refused to do so.

In justifying the Greens’ exclusion, the broadcasters argue that the party has not done as well as Ukip in recent polls and elections, and is unlikely to help form the next government.

Private negotiations are under way on the format of the leaders’ debates, and there has been an agreement that participants will not leak details of those talks.

Commenting on the poll, the Green party leader, Natalie Bennett, said: “It is clear from votes and polls that the public are fed up with the three business-as-usual parties and are looking around for alternatives. The public want a serious debate in which they hear the full range of views.

“They are well aware that austerity has failed even in its own terms while it has made the poor, the disabled, disadvantaged and the young pay for the fraud, corruption and mismanagement of the bankers.

“The Green party offers a positive alternative to the Westminster ‘business as usual’ approach to politics by the three main parties.”