It will be the first time since his first term began in 2010 that Mr McCormack heads to Parliament as a member of the Opposition, after Labor achieved a near-majority at the weekend.

Counting continues across the nation today but at a local level, both of the major parties lost ground in the Riverina electorate, with even the rate of informal votes rising to more than seven per cent.

Mr McCormack said he would serve and fight for the Riverina in either government or opposition and pledged to serve a full time as "voters don't like byelections".

The returning MP placed much of the blame for the shift against him in the polls on the larger field contesting the seat.

Voters faced a list of eight candidates on the ballot this election, compared to Mr McCormack running against just three opponents in 2019.

"We took a bit of a haircut, I acknowledge that, but we had twice as many candidates as last time, " he said yesterday.

Labor's Mark Jeffreson agreed with Mr McCormack's view that the increased choice at the ballot box played a part in his party's slide in first-preference votes.

An ALP government in power can only help grow interest in more change in the Riverina, Mr Jeffreson said.

"I think that Riverina will find themselves heartened by having a Labor government federally," he said.