The GMB union said there could be strikes over the summer from refuse workers if its members vote to take industrial action against Brighton and Hove City Council.
The union is locked in a dispute with the local authority over what it calls 'anti-trade union behaviour' from management in its refuse service Cityclean.
Read more: Bin strike looms in Brighton and Hove as union votes in favour of industrial action
Members were balloted earlier this month with 91.8 per cent of members who voted supporting strike action.
The union has now given council chief executive Geoff Raw the required legal notices to open a two-week industrial action ballot from Monday, June 3.
The formal ballot, if supported by members, could see strikes from refuse workers from July onwards.
The union said it wants the council to engage with it through mediators 'to assist in resolving matters around the recent issues and consequences arising from some anti-trade union management at the Cityclean Hollingdean depot'.
Gary Palmer, GMB regional organiser, said: "I’m just not sure that Geoff understands the need for, or even wants immediate action on the council’s part to resolve this matter, so while the GMB wait for Geoff and his management team to finish deliberating over diary availability, we find ourselves needing to move to protect our members position through enacting the formal industrial process, in case BHCC (Brighton & Hove City Council) filibustering continues.
"ACAS involvement in conciliation at Cityclean is the key to resolving what is for us, a serious threat to future industrial relations throughout the whole of the city’s workforce if not challenged now."
Mark Turner, branch secretary said: "When GMB are convinced that discussions, if or when they start are meaningful and that the chief executive and his team acknowledge that the behaviour of some of the Cityclean management has been anti-trade union when dealing with GMB reps and branch officials either purposefully or in error.
"Our members might in view of seeing a declining threat against those that protect and support them in the workplace, accept a recommendation from GMB to scale down, suspend or even halt the threat of action against their employer; otherwise unfortunately there will be disruption to the city’s streets and refuse services throughout July, August and September."
Brighton and Hove City Council has been approached for a comment.
The local authority has previously said ‘a strike would benefit no-one’ and said the action was 'unwarranted'.