George Osborne has defended the bedroom tax, saying it is ‘only fair’ to treat social housing tenants and private renters the same.

The chancellor of the exchequer, speaking to supermarket workers in Kent, said: ‘We have got 1.8 million families waiting for social housing and yet there are eight million spare rooms across the sector.

‘If you live in private rented accommodation and receive housing benefit, these rules already apply and have done for nearly 20 years.

‘You don’t get money for a spare room. Treating both groups of people the same, regardless of which landlord owns their house, is only fair.’

Under the bedroom tax, which came into effect yesterday, social housing tenants of working age with spare rooms will have their benefit deducted. Local housing allowance paid to private renters is already calculated on the basis of the number of bedrooms the claimant is considered to need.

Mr Osborne also defended the government’s wider reforms and criticised people who are against changes to the welfare system, saying they are on the wrong side of public opinion.

He said: ‘These vested interests always complain, with depressingly predictable outrage, about every change to a system which is failing.

‘I want to take the argument to them because defending every line item of welfare spending is not credible in the current economic climate.

‘Because defending benefits that trap people in poverty and penalise work is defending the indefensible.’

Mr Osborne said it is a ‘worry’ that nearly two million children live in families where no-one has worked. He said ‘the system became so complicated and benefits so generous, that people found they were better off on the dole than they were in work.’

He said: ‘We are simply asking people to make some of the same choices working families have to make every day.

‘To live in a less expensive house, to live in a house without a spare bedroom unless they can afford it, to get by on the average family income.’