Over 2000 workers at Queensland coal mines in north-eastern Australia operated by BHP Billiton are planning to go on strike.

BHP has been notified that workers at six mines owned by the BHP-Mitsubishi Alliance will roll out six-hour strikes on 14, 15 and 18 of June over a dispute on new employment agreement.

Broadmeadow, a seventh mine, settled an employment agreement last month, reports The Wall Street Journal.

If the strike begins, the mine workers will forego a A$5,000 ($5,308) one-off “sign on” bonus offered by the BHP-Mitsubishi Alliance in addition to a 5% wage hike.

Australian Manufacturing Workers’ Union (AMWU) said the decision to strike was taken after BHP-Mitsubishi Alliance refused to allow the union and two other labour unions to jointly bargain to halt work at the six mines that produce 3.5 million tons a month so that meetings could be held with the mine workers.

AMWU has sought for equal pay for contract workers, employees to receive equal wages and a say in the recruitment of workers in the mines.

The negotiations between the unions and the BHP-Mitsubishi Alliance are expected to run through end of July as the current employment agreement expires on 26 August.