Richard Price
BBC News, West Midlands
EPA
Mountains of rubbish piling up on Birmingham's streets have become a common sight
Bin worker strikes in Birmingham could last until December, after they voted to continue industrial action in a dispute over pay and jobs, according to union Unite.
On-and-off strike action began on 6 January with 12 walkouts planned across four months, and the union began an indefinite all-out strike on 11 March.
The union said on Wednesday its members voted by 97% in favour of continued strike action on a 75% turnout.
"The decision makers at Birmingham council need to get in the room and put forward an acceptable offer," said Unite general secretary Sharon Graham, warning strikes would continue for "as long as it takes".
"After smearing these workers in public since January and telling them to accept a fair and reasonable offer that never existed, the council finally put a proposal in writing last week," she said.
Ms Graham added: "True to form, the proposal came weeks late and was not in line with the ballpark offer discussed during Acas talks in May."
Last week Ms Graham claimed the deal had been watered down.
Birmingham City Council has been contacted for a comment.
Talks have been held under the chairmanship of the conciliation service Acas but the dispute has remained in deadlock.
Mountains of rubbish heaped up on the city's streets have led to concerns over public health and the environment, and there have been queues of up to a mile at some mobile collection points as residents try to get rid of their waste.
PA Media
On-and-off strikes began in January with all-out action from 11 March
The dispute initially centred on the council's decision to remove Waste Recycling and Collection Officer (WRCO) roles but escalated amid anger over an alleged move by the local authority to hire temporary labour which the union claimed would "undermine" the walkouts.
The union has claimed about 170 workers faced losing up to £8,000 a year - but the council disputed the figures.
The local authority claimed the number of staff that could have lost the maximum amount of just over £6,000 was 17 people, and they would have pay protection for six months.
The dispute has since grown to include issues over the pay of bin lorry drivers.
In April, the union said, under new council plans, bin lorry drivers' pay could also fall from £40,000 to £32,000.
The council said it was carrying out a "fair and transparent job evaluation process" agreed with trade unions, to comply with equal pay laws.