Federal minister Barnaby Joyce hurt the Nationals' chances of winning a rural Victorian seat in the state election, outgoing leader Peter Ryan says.
The state seat of Shepparton - which has been held by the Nationals for 47 years - could be won by an independent as counting continues.
Mr Ryan pointed to an intervention by the agriculture minister - the deputy leader of the federal National party - who said it was up to the Liberals and not the Nationals to fight for food processor SPC Ardmona to stay in the region.
"Barnaby had some less than helpful things to say in that final week in Shepparton," Mr Ryan told reporters on Monday.
"It all bubbled over, it was unnecessary and I don't know to this day precisely what he was trying to convey."
Mr Ryan said the Victorian Nationals were pivotal in securing a $22 million package that had ensured the processor, a major employer in Shepparton, stayed open.
"I was annoyed and they were unhelpful," Mr Ryan said of the comments.
"I'm sure it was a factor that was playing out in people's minds."
Mr Ryan, who led the Victorian Nationals for 15 years, will stand down at a party meeting within days.
He was also deputy premier in the Napthine government, which lost the state election on Saturday.
Mr Joyce, however, refused to accept his comments led to the big swing against the Nationals in the seat.
When asked later in parliament by Queensland MP and former Nationals member Bob Katter if he accepted responsibility, Mr Joyce insisted the state Nationals had helped the company.
"It is interesting to note that there is actually a package for SPC and it was delivered by the Nationals and was delivered by Jeanette Powell," Mr Joyce said, referring to a $22 million boost given to the company by the state government.
Despite requests, the Abbott government refused to offer the company financial assistance.
Ms Powell was the state member for Shepparton but did not contest what had been a safe coalition seat for 47 years.
Mr Joyce said the Victorian government was able to assist SPC because it was able to deliver a surplus, whereas his government was left having to clean up the financial "car crash" left behind by the former federal Labor government.
