Members of the Transport and General Workers Union (TGWU), working for the company FOCSA, were balloted on Tuesday.

The firm provides waste collection services for Allerdale Council.

Union members say a new two-tier pay system is unfair to former council employees. Nobody from FOCSA was available for comment.

'Amicable solution'

The settlement would mean a difference in pay rises for FOCSA staff and workers taken on from the council when services were privatised, according to the TGWU.

Union spokesman Alan McGuckin said: "The basic unfairness of this pay offer would create a divided workforce.

"Staff on both sides of the settlement are angry about this.

"We will be taking action on this issue until the company sees sense."

A small number of staff who are members of general workers' union, the GMB, will also be balloted.

Mr McGuckin said he expects the results of that ballot to reflect the TGWU vote.

He said the results will be known on 1 September and he expects strike action within14 days of that date.

An Allerdale Borough Council spokesman said: "Obviously, the council does not employ the workforce. However, we do have a responsibility to ensure that the public gets its refuse collected and streets cleaned.

"We would therefore encourage both sides to get together and find an amicable solution as soon as possible."