Brighton and Hove Green Party members protested outside the Treasury about cuts in council grants and spending.
They handed in a letter urging the Chancellor George Osborne to give more financial support to councils as they faced rising demand for services.
The Green Party said: “The colourful protesters brought a collection of musical instruments, drums and other noisy apparatus in an effort to wake up the Treasury to the reality of cuts facing cities like Brighton and Hove.
“The letter delivered to the Treasury highlighted major cuts expected to be made by the Labour council over the next few years, including £20.5 million of cuts to adult social care, an £8.7 million cut to child safeguarding and care and a £2.4 million cut to special educational needs and disability services.
“Many cuts to preventative services are expected to drive up longer-term health costs, including a £1.3 million cut to homelessness prevention, £1.3 million cut to support for residents with substance misuse problems, £846,000 cuts to children’s centres and a £498,000 cut to sexual health and HIV services.
“In their letter to the Treasury, Greens request that the government conducts a comprehensive review of local government finance arrangements which takes into account the rising cost of delivering local services in Brighton and Hove.
“Greens point to massive service pressures from increases in demand for support for adults due to a recent court case on deprivation of liberty, increased pressures on children’s services due to an extraordinarily high rate of child protection plans and an out-of-control housing crisis requiring increases in interventions to prevent homelessness.”
Phélim Mac Cafferty, convenor of the Green group on Brighton and Hove City Council, said: “The latest round of Tory government cuts spell disaster for residents of Brighton and Hove as the support grant given to the council effectively disappears.
“This will lead to massive cuts across the board, from help for struggling new parents to preventative work for troubled youngsters and horrendous cuts in social care for disabled and older people – all at a time when the city is seeing unprecedented levels of demand for its services.”
Councillor Mac Cafferty added: “Despite the Tories promising that councils will be able to keep 100 per cent of business rates they raise, this will not come into effect until 2020, well after frontline services will have been slashed.
“And what may be given in one hand is quickly taken from another as councils are prevented from raising rates to meet additional responsibilities imposed by government.
“The spending review has been a smoke and mirrors exercise by a government that hopes people won’t ask too many questions.
“The people of Brighton and Hove aren’t fooled and we urging the Treasury to recognise the devastating reality facing local government.”
Brighton Pavilion MP Caroline Lucas said: “These cuts to local authority grants will unleash further devastation to communities across Britain.
“In Brighton my constituents are facing the hollowing out of council services, including the proposed closure of up to five children’s centres.
“Enough is enough. The government must rethink its callous and counterproductive austerity programme and give local authorities the resources they need to deliver services to the people they work for.
“I fully support Green councillors in standing up for their constituents.”