The Kiama by-election date is not yet known but the campaigning has already begun with NSW Minister for Climate Change and Energy Penny Sharpe challenging the Opposition on its stance on renewable energy.

Sharpe issued a statement on Monday morning to question whether the Liberal or National candidates in the upcoming poll will "stand for renewable energy or against it".

"Will they take the Liberal position and vote in favour of renewable energy legislation, or the Nationals' position – resolutely against it," she asked in the statement.

"Last week, the Liberals and Nationals split on the floor of Parliament when the NSW Government introduced legislation to ensure we can continue the important work of accelerating projects that will get more reliable, clean and affordable electricity into the NSW energy grid.

"The Coalition is now in open conflict over renewables, and fighting over who will even run in Kiama.

"Voters deserve to know whether its candidate will back cheaper, cleaner and more reliable energy.

"Will it be a Liberal candidate who supports more renewables? Will it be a Liberal candidate against more renewables? Or will it be an anti-renewables National party candidate?"

Sharpe claimed the Coalition cannot put up a candidate without outlining its position on this issue.

"The Nationals have already walked away from the bipartisan NSW Electricity Infrastructure Roadmap – a plan they introduced in government and re-supported – undermining years of progress," she added.

"Support for renewables means taking action on climate change, keeping the lights on and putting downward pressure on electricity prices.

"Kiama can’t afford a candidate who sits on the fence.

"The Coalition must name its candidate – and make its position on renewables crystal clear."

A date on the by-election is expected to be announced by the end of the week following convicted rapist Gareth Ward's resignation last Friday less than an hour before NSW Parliament was due to vote him out because of "unworthy conduct".