Refuse collectors, park attendants and some street cleaners in Plymouth are to be balloted over possible industrial action next week.

The unite union says while many workers accepted proposed changes to their overtime pay, this group of staff did not.

The local authority is proposing to remove contractual overtime - this is where staff are given an additional payment to stay late and unload vehicles.

In future, all of these tasks would have to be carried out during the normal working week.

The city council says overall GMB, Unite and Unison did accept their proposals.

They add that the changes will allow them to save eighteen million pounds over three years.