?Impossible task?: NSW Labor to contest byelection in John Barilaro?s seat of Monaro

NSW Labor will contest the Monaro byelection, prompted by the resignation of former deputy premier John Barilaro, despite calling victory an "impossible task".

The opposition leader, Chris Minns, on Friday announced the party would put up a candidate for the Nationals-held seat, in one of five electoral battles sparked by a spate of resignations in October.

"Labor hasn't held the seat for 10 years. It will be an impossible task," he said.

"[We] will have a mammoth task ahead to regain the trust of voters.

"But we believe voters deserve a choice about who represents them - and to send a message to the Liberals and Nationals."

Barilaro won the seat off Labor in 2011, and currently holds the electorate on a 2.5% margin.

A candidate is yet to be determined but Minns will visit the electorate over the weekend.

Days after former premier Gladys Berejiklian resigned her leadership in October under a cloud of corruption allegations, the then Nationals leader, John Barilaro, announced he would follow her out the door.

Since then the transport minister and Bega MP, Andrew Constance, has announced he'll quit state parliament for a tilt at a federal seat, as will the MP for Holsworthy, Melanie Gibbons.

Jodi McKay, who stood down as Labor leader following poor results in the Upper Hunter byelection in May, has also announced she wants out of politics.

No date has been set for the five byelections, which NSW Labor last month called a waste of taxpayer money amid the pandemic.

The party has since announced it will also contest the seat of Bega - which neighbours Monaro - painting themselves as the underdogs in that battle too.

"It will be almost impossible to win, but the people of Bega deserve a choice," Minns said at the time.