Helen Clark faces a crucial vote later on Monday night (NZT) as she vies for the United Nations' top job.
In the last straw poll, she was knocked back to seventh place - and another blow like that is expected to end her campaign.
Blocking John Key in 2013, now it looks like Vladimir Putin will also block Helen Clark from her bid for Secretary General.
"There's no secret that Russia believes it's the turn of the Eastern candidate," he said.
Key and Foreign Minister Murray McCully have been lobbying hard for Clark, but on Monday Key said the Government had given up on convincing Russia to back Clark.
"It's either going to improve for her later in the week, or it's going to get a bit tougher."
The fast-approaching straw poll is third in this year's campaign - its purpose to test the viability of the candidates.
Each of the 15 Security Council members cast one of three votes - "encouraged", "discouraged" or "no opinion" for the 10 remaining candidates.
Votes recorded for or against a candidate are made public, but how each country voted remains a secret.
And when it gets to the actual vote, the all-important permanent five members have the option of blocking any candidate.
John Key says that may happen to Clark "if they're protecting their own interest - and while we understand that, we don't support that view".
There is speculation the next Secretary General could come from the Eastern European group, but tension between Russia and Western P5 members could offer other candidates a serious chance.
If US-backed candidate Susana Malcorra is vetoed by Russia and Moscow's preferred choice Bulgarian Irina Bokova is vetoed by the US, Clark could sneak in.
"She could be seen as a very safe pair of hands coming through the middle," Key said.
With the third straw poll just hours away, Clark will be hoping her rankings improve this time around - otherwise there is a chance she might pull out altogether.