Union Unite is asking staff at the cement giant’s Rugby, Warwickshire and South Ferriby works whether they want to be balloted.

Unite is challenging the decision to close the defined benefit pension scheme to existing members and claims its defined contribution scheme provides less benefits than Cemex’s two main rivals.

The union claim Cemex has refused to enter discussions about the pension scheme.

But a spokesman for Cemex UK said: “We can confirm that we have entered into consultation with our employees and recognized unions about a proposal to close our defined benefit pension schemes to future accrual for active members.

“There are ongoing consultations with affected employees and Unite and all feedback will be evaluated before any final decisions are made.”

Unite, national officer John Allott said: “Unite is to ask workers at Cemex if they are prepared to take part in an industrial action ballot over pensions.

“We understand that the status quo is not an option but the company are refusing to negotiate with the union to achieve decent pensions for all its employees. We hope that the company will now get round the table and negotiate in good faith.”