Refuse collection vehicle drivers in Barking and Dagenham are continuing industrial action after an attempt at mediation failed.
Union officials from GMB, Unite and Unison and Barking and Dagenham Council officers attended the conciliation service Acas on 21 April but the two sides did not meet face-to-face.
The unions say their members face a £1,000 pay cut, and will strike on 23 and 24 April with the potential for eight more days from 1 May.
A further session at Acas for the councils and unions is schedued for 28 April.
Paul Hayes, GMB regional secretary, criticised the council over the 21 April talks, saying: “Managers were not prepared to even meet the GMB or their own employees in the same room to solve the dispute.”
Barking and Dagenham responded with a statement saying the three council officers in attendance were hoping to negotiate, but the discussions were halted because the GMB would not speak to the other unions.
The statement read: “We asked the GMB to suspend the planned strike action while we worked out a solution with them, Unison and Unite. They refused to suspend the strike or engage with the other trade unions.
“We believe it is possible to make progress next Tuesday as further strikes are in no-one’s interest, particularly our residents and businesses.”
Strike action has already taken place from 18-20 March and 7-8 April over this dispute.