Ron Mark has claimed National party leader Simon Bridges tried to do a deal with him over the Wairarapa seat.
The New Zealand First MP and Defence Minister says the conversation happened in May, but Mr Bridges says it never happened.
"Simon and I were next to each other on a flight from Auckland to Wellington in May. He brought it up out of the blue during a conversation we were having," Mr Mark said.
- Jacinda Ardern sets sights on 2020, angles for deal with NZ First in Wairarapa
- National MPs singing from the same song sheet on Bridges' expenses
"He was just sounding me out about a deal in general, involving the Wairarapa. He didn't get into the specifics of what that might look like. I laughed it off before he could go any further.
"New Zealand First doesn't do deals, so I didn't entertain the thought."
The Wairarapa seat has been held by National's Alistair Scott since 2005. He won it last year with a majority of nearly 3000, with the remaining votes split between Labour's Kieran McAnulty and Mr Mark.
Party leader Winston Peters made the same claim about the deal to NZME, but Mr Bridges is adamant he never discussed it.
"No. This is yet more fake news from Winston Peters," he told Newshub.
On the other hand, as Newshub reported yesterday, if Labour made a deal with NZ First and Mr Mark didn't stand they could beat out National by nearly 5000.