LISTEN ABOVE: The voice of America, UN Correspondent Margaret Basheer speaks to Larry Williams about the third straw poll.

The Government's ready for some last minute lobbying, to try to build support for Helen Clark's bid to be UN Secretary-General.

Another straw poll is being held tonight, but Miss Clark is currently not seen as a front-runner.

Prime Minister John Key heads overseas next week for the East Asia Summit, and said he will take the opportunity to speak with UN heavyweights Russia and the US.

He said he's already discussed it with President Obama, but he'd want to speak to him again.

"I've had a discussion with President Obama already and I probably look to follow up that conversation."

Mr Key said he'd also raise it with Russia, but they've been clear that they want an Eastern European in the role.

Mr Key said New Zealand's not compromising its United Nation's agenda in order to back Helen Clark's bid for the UN's top job.

He said Ms Clark's campaign is not affecting the issues New Zealand is trying to push on the Security Council.

"We're not holding back our punches because we are trying to support Helen Clarks candidature."

Meanwhile, with another vote on the UN Secretary General candidates pending, Mr Key said he doesn't have a particular threshold where he thinks it would be a good idea for Ms Clark to either stay in or get out of the race.