About 100 coalminers have won the right to convert from casual to permanent employees, along with better pay and conditions, in a victory ending an industrial stand-off.

The Construction Forestry Maritime Mining Energy Union confirmed the deal for workers at Wongawilli Colliery, a Wollongong Coal-owned mine near the NSW coastal city.

Casual workers’ rights is shaping as a key issue in the industrial relations policy battle ahead of this year’s federal election.

After CFMEU members decided to go on a two-week strike on Monday, a deal was struck on Wednesday, with workers securing a 12 per cent increase in the hourly pay rate and a 12.5 per cent boost to the bonus rate.

The deal lifts them from low-paid casuals to permanent employees with comparable pay and conditions to other coalminers in the region.

Union membership at the site soared from 13 to 80 over nine months, prompting the workforce, which is outsourced to labour hire firm CAS Mining, to seek an enterprise agreement.

Under a new two-year agreement with CAS coalminers at the site will also get an annual two per cent pay increase.

CFMEU mining and energy southwestern district vice president Bob Timbs said the “massive” victory was a crystal clear example of union power.

“These were un-unionised, casual workers who were being exploited by their employer. They were the lowest paid labour hire casuals in the region,” Mr Timbs said.

“Through joining their union and flexing their collective muscle they are now permanent employees on pay and conditions consistent with the area.”

Labor has promised to ensure labour hire workers are guaranteed the same pay and conditions as direct employees if it wins the federal election.