After a return to work on February14 after a week-long lockout by mine owners Xstrata, the miners returned to the picket lines on Thursday over a pay and conditions dispute.

Construction, Forestry, Mining and Energy Union executive Lee Webb said that on Monday miners rejected the management offer by 230 votes to 1.

Mr Webb said Xstrata had tried to force a workplace agreement on the workers.

The union negotiating team had been denied any input and it was the same offer previously rejected by the union.

Miners returned on Saturday and Sunday for half-day shifts

Full shifts were resumed on Monday night.

On Thursday Mr Webb said the long-running negotiations, which began in October 2008, had turned into a nasty dispute.

``We're striking because the company won't talk to us,'' he said.

Xstrata spokesman James Rickards said the union's demands were out of touch with industry standards.

``The CFMEU is demanding a 2010 pay increase for 1980s restrictive workplace conditions,'' he said.

``This is not in the interests of our people or the viability of the operation.''