During his victory speech to family and supporters at Wagga's Murrumbidgee Turf Club on Saturday night, Mr McCormack thanked the National Party volunteers who attended every one of Riverina's 83 polling locations and said his opponents had generally run a respectful campaign.

"It's with great pleasure that I announce that the National Party has been re-elected to the division of Riverina with most of the polling booth results in to the Australian Electoral Commission," Mr McCormack declared around 9.30pm, less than four hours after the polls closed.

"It's very pleasing to say that the Nationals will continue the fine representation of the Riverina division that we have provided for many, many years."

Mr McCormack retains the seat with 46.76 per cent of the primary vote, representing a 12.62 per cent swing against him compared with the 2019 federal election.

Labor's Mark Jeffreson was on 20.5 per cent, representing a 2.66 per cent swing against him.

The Riverina two-party preferred last night stood at 65.11 per cent for Mr McCormack and 34.89 per cent for Mr Jeffreson.

The number informal votes rose to 7.17 per cent, up more than two percentage points on the 2019 election. The participation rate also dropped, with a turnout of 82.13 per cent compared to a 2019 effort of more than 93 per cent.

Mr McCormack said the he was pleased to see the results of the National Party's efforts in government represented in the Riverina result, particularly over the past three "very difficult" years.

"We started with a drought, we had bushfires, we had floods, we had a mouse plague and of course not to mention the coronavirus," he said.

"This has been an unprecedented, trying time for Riverina people and for people across Australia."