Forget trading jabs over the cost of baby bonus schemes - our two main political leaders are now embroiled in a sixth-form scrap about who can handle the most booze.

Prime Minister John Key downed several cups at Auckland's Big Gay Out over the weekend during a "beer pong" session.

This morning, the PM told the Herald he would "definitely" beat Labour Leader David Cunliffe at the drinking game. He said he would “definitely win” a game of beer pong against Labour leader David Cunliffe.

“Wouldn’t be any doubt about it,” the PM said.

Not be outdone, Mr Cunliffe told media he would win a beer pong battle against Mr Key.

"I could, I'm sure - if the moment arose - drink him under the table. I have body mass on my side," the leader of the opposition said.

It's going to be a long election.