Helen Clark's potential rival for the UN's top job, former Australian Prime Minister Kevin Rudd, has tweeted best wishes to her on the announcement of her candidacy for secretary-General.

"I've worked closely with Helen as PM & at UN. Helen will be a strong UNSG candidate and I wish her well," he said in his tweet.

Mr Rudd, however, has the potential to weaken a Clark bid, either with his own campaign or by not making his intentions clear.

And former New Zealand Prime Minister Sir Geoffrey Palmer said having Australia and New Zealand supporting different candidates would not be a good thing.


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"I think the Australian question will be quiet important here. I don't know whether Mr Rudd is going to run or not. Having New Zealand and Australia supporting different candidates is not such a good thing."

He said he would like to see Australia supporting Clark, even if Mr Rudd ran for it.
Australia's Liberal Government would probably feel obliged to back the former Labor Prime Prime Minister if he sought a nomination.

But a less than friendly gesture at the weekend, Australian Foreign Minister Julie Bishop outed Mr Rudd's stealth campaign for the UN job, revealing she had learned he had been approaching foreign leaders asking for their support.

Mr Rudd was ousted by his own colleagues as Prime Minister. He won the job back after undermining his own nemesis, Julia Gillard, but was rejected by the public at an election in 2013.

Australian Immigration Minister Peter Dutton told News Corp that Mr Rudd's bid must be "driving people crazy."

"No world leader is safe -- when 'Kevin Rudd' comes up on their caller ID they must grit their teeth and say 'please not again'," Mr Dutton said.

"Kevin, mate, cobber please stop driving these people crazy -- do what other people do in retirement and play golf or buy a caravan."


One of Mr Rudd's former Labor colleagues, former Education Minister Peter Garrett, has tweeted in support of Helen Clark saying she would make an excellent UN boss.

"She's got the right attributes to make a contribution on a global scale. Go Helen!"
Before entering politics, Mr Garrett was in the band Midnight Oil.