The New South Wales Liberal Party has been hit with a 29 percent swing against their primary vote in the Wagga-Wagga by-election, becoming the third largest swing against the party in state history.

Blame for the loss of the historically safe Liberal Seat is being put by the Party on the ousting of Prime Minister Malcolm Turnbull last month, as well as allegations of corruption surrounding MP Daryl Maguire.

The New South Wales Premier also faced criticism from her Coalition partners, who said a Nationals candidate should have been allowed to contest the seat.