Birmingham City Council has approved plans to hike council tax by 21% over the next two years.
Councillors also voted in favour of £300m in cuts over the same period.
The Unite union described the move as “devastating for Birmingham council’s workers and the entire city”.
It comes after the local authority effectively declared bankruptcy last year after being hit with a £760m bill to settle equal pay claims.
In September town hall officials issued a section 114 notice, confirming that all new spending, with the exception of protecting vulnerable people and statutory services, must stop immediately.
Following the vote on Tuesday night, Unite‘s national officer for local authorities Clare Keogh said: “Vital public services are on the brink of being all but destroyed.
“This is the culmination of years and years of brutal budget reductions by central government.
“Birmingham council’s workers, who have already suffered well over a decade of falling wages and whose efforts have ensured increasingly depleted services functioned, must not pay the price for a crisis they didn’t create.”
The Labour-run council is the largest local authority in Europe.
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