Every employee at Preston Council will be paid at least £7.45 an hour under radical plans.
But stunned Tory councillors warned the plans, pushed through by jubilant Labour members and four Lib Dems, would mean job losses.
Preston will become one of only a handful of UK local authorities to adopt a "living wage" after it was voted in by 29-26 at yesterday's full council meeting.
A total of 101 out of 1,600 employees will get a pay rise and the council will urge contractors to also pay workers that amount.
But several Tory and some Lib Dem members said it had come at the "wrong time" and could lead to "two or three people" being made redundant to find the £48,800 needed to fund it next year.
Coun Matthew Brown (Lab), who proposed the motion, said: "It is nothing, it is about 40% of the chief executive's salary and for that we can help 101 low paid staff.
"It could bring thousands of people out of poverty."
Labour group leader John Collins said the council should be looking after all its employees in the same week as it is trying to sign up a Guild supremo on a wage of close to £80,000.
Coun James Hull (Lab) said the council would "demonstrate to other employers that we actually appreciate the people we employ at every level".
But Coun Bill Shannon, whose Lib Dem party had a free vote, said: "Let's be clear, what we are talking about here is making two or three people redundant to afford that £40,000."
Council leader Ken Hudson, who looked dismayed at the result, said the authority had just pumped £2.7m, with another £500,000 to come, into employee wages following a job evaluation.
All Preston Council employees earn more than the current minimum wage of £5.73 an hour for adults over 22.
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