The spectre of the holocaust was raised in a spiteful Question Time in Federal Parliament, with the Opposition likening the phrase "climate change denier" to the Nazi genocide of Jews.

Prime Minister Julia Gillard described Tony Abbott as a climate change denier - a frequent political barb used against the Opposition Leader.

But the Manager of Opposition Business, Christopher Pyne, took a point of order.

"I think the words being used by the Prime Minister would be regarded as offensive words," he said amid rowdy scenes.

"We all know the connotation the Prime Minister is trying to bring about by using the word 'denier'.

"We know she's trying to allude to the holocaust. It is offensive and it must stop."

Speaker Harry Jenkins said he had to use "all the sensitivity" he could muster to hush the House.

"I think that the construction the Manager of Opposition Business has placed at this point in time is stretching it," he said.

But Mr Pyne was not prepared to leave it there.

"Mr Speaker, with 18 years in this place I don't think anybody would accuse me of making light of the holocaust or any issue to do with the state of Israel," he said.

"I was 11 years as chairman of the parliamentary friendship group on Israel. I make the connection between climate change denier and holocaust denier.

"I find it offensive and I'm sure the Leader of the Opposition finds it offensive. In that spirit I would ask you to ask [Ms Gillard] to withdraw it."

But the Speaker would not be moved - and delivered a reprimand to both sides.

"I simply say to the House that actually having come to this flashpoint I would hope that members take a deep breath and behave in a manner that those that observe us from outside would expect," Mr Jenkins said.

"That would apply to both sides actually turning down the heat, turning to the basics of what we are here for.

"That is to debate the issues and not get into the personality clashes that we are seeing over many question times.

"Regrettably, we are judged by this hour-and-a-half of our proceedings."

But neither would Mr Abbott leave it alone.

"I find the Prime Minister's statement both untruthful and offensive. If you don't wish to ask her to withdraw Mr Speaker, I just want to place on record it is both untruthful and offensive," he said.

Mr Jenkins wanted no more of the issue.

"I hope that the whole membership of the House would see this as a full stop," he said.