Seven months after the introduction of the so-called ‘bedroom tax’ two thirds of council house tenants affected are behind with rent, a Freedom of Information request has found.

Rent arrears have risen by £693,202 to £4,182,026 since the welfare reform’s introduction in April. It cuts housing benefit by an average £14 per week to council and housing association tenants deemed to have ‘spare’ bedrooms.

Of 2,920 Bristol council households affected, 1,990 are behind with rent, and 250 have received a Notice of Seeking Possession. Landlords must issue secure tenants with these documents – usually triggered when arrears reach eight weeks’ rent – before they can apply to court for eviction proceedings.

Most given a notice had some level of arrears when the legislation came into force, but 14 owed nothing. Thirteen of these have continued to slide further into debt, and one has already been referred to court – as have an unspecified number of others who already owed money to the council.

Just over 100 tenants have managed to transfer or exchange into a smaller social home. In September a cross-party group of councillors convened by George Ferguson recommended scrapping a temporary ‘no evictions’ policy in place since March.

A spokesperson for Bristol Citizens’ Advice Bureau said the council – which has more than £600,000 of its discretionary housing hardship fund left – was working with people to manage their situations.

“Low numbers of people have been served a notice solely because of the bedroom tax so far,” he said. But he warned that for others with previously clear rent accounts, “arrears are probably going to approach the eight weeks’ rent level in November or December”.

A number of tribunals elsewhere in the UK have recently overturned individual bedroom tax decisions, with some housing lawyers suggesting the policy could be in for a rocky ride in the courts. Protesters in Bristol – who will stage a rally and hand in a 3,500-signature petition to City Hall today at 1pm – are urging tenants to appeal and have produced a leaflet explaining how to do so.

Dave Weltman, who co-ordinates campaigning activities in Bristol, said: “The suffering caused by the bedroom tax is now well documented in thousands of individual stories of hunger, stress and homelessness, not least those of disabled people who make up two thirds of those affected.

“As we head into a winter of further planned rises in gas prices, this tax will sharpen the ‘heat or eat’ dilemma for numerous poor households.”