Almost all questions posed to Joe Hockey this morning by the crowd at Mary Mackillop College Hall were sceptical of Julia Gillard's planned tax or supportive of the opposition's plans to wind it back.

MC Gary Hardgrave, a former Howard government minister and current Fairfax Radio 4BC drive presenter, described the reaction of the 300-strong crowd to Mr Hockey's speech as similar to "an old fashioned revival meeting".

Mr Hockey attacked the policy as a "bad tax" which would "hurt the nation" and called out Treasurer Wayne Swan for earlier promising that the tax would not impact on the federal budget.

The tax is expected to cost an extra $4 billion to fund over the next year.

"If Wayne Swan sees a $4 billion hole in the budget as a rounding error, then he and his government have got to go," he said

Mr Hockey said merchants at a Brisbane market this morning told him they would not be able to pass on the cost of an estimated 10 per cent rise in electricity without sacking staff.

"Time and time again, as we went past every store, all the workers were coming out and saying 'you have to stop this tax'," he said.

Mr Hockey's address was met by resounding cheers from a largely partisan crowd before audience members reacted angrily to the government's decision not to take the tax to an election.

One audience member drew parallels with the American revolutionary war, echoing the slogan of "no taxation without representation".

"What is the Coalition going to do to try and stop the people of Australia taking up arms against their government the way the Americans took arms up against their government 200 years ago?" he said.

Mr Hockey said he understood the man's anger but said Australians were a peace-loving nation who fought with words.

He promised to do everything he could to stop the tax and encourage protest against the policy.

Elsewhere, a show of hands was held to see if audience members believed "man [had] warmed this planet in the way that the apparent consensus of scientists say".

Only a handful of those in attendance raised their hand.

With the prevailing mood in the hall against the tax, a lone voice asked what a Coalition government planned to do address climate change, Mr Hockey pointed to their direct action plan which he said would focus on reducing emissions without hitting Australian tax payers in the hip pocket.

Liberal Senator George Brandis said the town hall meeting was just the beginning of a campaign against the tax in Labor-held seats.

"There will be spontaneous gatherings like this happening in every Australian city and town this week, today, tomorrow and the rest of the period until parliament goes back," he said.

Held just a few hundred metres away from treasurer Wayne Swan's Nundah electorate office, organisers had invited the deputy prime minister to take part in the forum.

But he was nowhere to be seen, a sign bearing his name drawing attention to his non-attendance.

Among the political figures in attendance were Queensland federal Liberal MPs Wyatt Roy, Andrew Laming and Teresa Gambaro.