Thousands of Brighton and Hove’s poorest working age households will have to pay up to 76% more council tax.

Councillors narrowly voted through a Labour-led amendment which will see the minimum council tax contribution expected of 16,000 of the city’s families rising from 8.5% to 15%.

Green councillors voted against the amendment and said making the city’s poorest pay for central Government cuts was “shameful”.

But councillor Warren Morgan, Labour group leader, described the increase as responsible and said the authority would still ask less from their poorest households than many other councils in the country.

The current council tax reduction scheme – formerly known as council tax benefit – would leave a £4 million funding gap by the end of 2015/16 – rising to £11 million in 2019/20.

The agreed rise will mean the average affected household will have to pay £43 a year more with families in band D homes having to find £100 more.

The Labour amendment includes increased support for the disabled and carers.

Amendment The initial proposal by the Greens would have seen the contribution remain at 8.5% funded by a council tax rise of 5.9%.

In a 25 to 22 vote in favour of the amendment four Conservative councillors, Tony Janio, Denise Cobb, Graham Cox and Dawn Barnett, abstained, while former Labour councillor Leigh Farrow, who confirmed his defection to Ukip to The Argus prior to the council meeting, voted against his former party.

Councillor Ollie Sykes, Green lead member on finance, said the council tax reduction scheme was a perfect example of local government minister Eric Pickles’ localism policy, where the Government keeps the money and councils take the blame.

Fellow Green, councillor Leo Littman, called the amendment “Labour’s shameful poor tax”, while colleague Pete West described it “as an attack on the poorest in the city”.

Coun Morgan said the council’s current tax reduction scheme was among the top six most generous schemes run by unitary authorities, dropping to the top 12 with his party’s amendment, and still more favourable than 40 councils already asking their poorest residents to pay up to 40% of their council tax bills.

He added: “This is an amendment we wish we didn’t have to propose but, in the circumstances we face, it is the reasonable thing to do.”

Councillor Geoffrey Theobald, Conservative group leader, said the issue had arisen as both the Greens and Labour had avoided making difficult decisions on how the council is run to court the “left-wing vote”.

Coun Janio said he could not back an increase in the amount paid by the poorest while the council employed 500 managers and more than 9,000 members of staff.