The soon-to-be father of seven children and Wangaratta small businessman has slotted in behind the electorate's two main protagonists, Cathy McGowan and Sophie Mirabella, and is poised to pounce if voters decide on Saturday they want to take a different direction.

He is the first Nationals' candidate to contest Indi since Mrs Mirabella was elected in 2001 and as was the case 15 years ago, Mr Corboy's chances rest on whether he can climb ahead of his Coalition stablemate and take on Ms McGowan in the preference stakes.

"We have an important decision to make as an electorate and I really do believe I am the best candidate to take the aspirations of the people of Indi to Canberra," he said.

"If I am elected I will join a hard-working National Party team which will continue to deliver to Indi.

"If I can secure funding for the Rutherglen bypass as a candidate, imagine what I can do as the member for Indi with the ears of relevant ministers to our region.

"But it has been a very long campaign and like a lot of people in Indi, I'm glad it is coming to an end."

The last time the Nationals' contested Indi they polled just 12 per cent of the vote.

The age difference between Mr Corboy and the late Don Chambers, who was the National candidate in 2001, is close to 30 years.

But Mr Corboy would have to double the party's primary vote to get ahead of Mrs Mirabella, who achieved 45 per cent of first preference votes three years ago, but was still run down by the independent.

Further complicating matters is the presence of a Country Party candidate in the race, Julian Fidge, who will also be vying for the rural vote.

The late Mac Holten was the Nationals' last Indi MP in 1977.

Deputy Prime Minister and National Party leader Barnaby Joyce has been on the ground in Indi with Mr Corboy twice and Federal Transport Minister Darren Chester has made three visits.

Mr Corboy will begin election day in Benalla before travelling to Wangaratta where he will vote alongside his wife, Annelisa.

He will then travel to Wodonga, the largest population base of the electorate, before returning to Wangaratta.

Former Nationals' state member for Benalla, Bill Sykes, has been watching Mr Corboy's campaign closely.

"I've been extremely impressed that he has remained true to himself," Mr Sykes said.

"He is a decent person who engages easily with the full spectrum of people in the electorate.

"The campaign strategy has been to promote Marty's qualities and what he can do as part of the Nationals' team in Canberra if elected and remain positive at all times.

"He has stuck to the game-plan.

"I think he is a better bet than the bookies odds show."