Refuse collectors who took part in a three-month strike in 2017 are to stage fresh walkouts in an escalating row over pay.

Members of Unite at Birmingham City Council have been banning overtime and working to rule since the end of December, after the union said workers who did not take part in the previous strikes had been given extra payments by the authority.

The union announced that its 350 members involved in the dispute will strike for two days a week from February 19.

The council has said it offered binding arbitration to resolve the row, and talks were held at the conciliation service Acas.

Howard Beckett, Unite’s assistant general secretary, said: “This dispute is entirely of Birmingham Council’s making, following a decision to pay extra money to a small group of workers who did not take strike action.”

The council has already announced changes to its contingency plans because of the work to rule, including a temporary, fortnightly service.

A spokesman said payments to workers were as a result of a failure to consult during the negotiations that ended the 2017 dispute, adding: “They were not payments for working during the industrial action.”

A Birmingham City Council spokesman said: “We utterly refute the allegations made and are extremely disappointed that the reasonable offer we have put forward has been rejected by Unite on behalf of their members.

“The Unite statement is not in the spirit of ongoing discussions at Acas, but we remain committed to resolving this dispute and the offer is still on the table.

“To be absolutely clear, we have not blacklisted or discriminated against Unite members. The council condemns blacklisting of any sort.

“As previously stated on a number of occasions, the payments to GMB members were properly made for a failure to consult during the talks that ended the 2017 dispute.

“We would urge Unite to continue talks as we want to resolve this matter, so citizens get the refuse collection service they rightly expect and deserve.”

Mr Beckett added: “The decision to escalate the dispute and begin strike action is a direct result of Birmingham Council’s failure to treat our members fairly.

“Rather than settle this dispute and end the discrimination the council has instead chosen to try to utilise anti-trade union laws and is penalising workers who have been taking industrial action by denying them their holiday requests.

“Unite’s members have taken the decision to move to full strike action as a last resort due to the council’s refusal to make a fair offer to resolve this dispute.

“This dispute is entirely of Birmingham Council’s making and it is in the council’s hands to come forward with a solution to end the discrimination experienced by Unite members. If they fail to do so then the city’s residents will regrettably experience further disruption to their refuse service in the coming weeks.”

Strike dates announced by Unite are February 19, 22, 27, 28 and March 4, 8, 12, 13, 21 and 22.