The government wants to call it the “spare room subsidy”. Almost everyone else calls it the bedroom tax – a move to cut housing benefit paid to some people who rent from a council or social landlord, depending on the number of bedrooms they have.

David Cameron took exception to the phrase “bedroom tax” at Prime Minister’s Questions today. It’s not a tax unless you’ve earned the money first, he said.

The government’s case for reform is that the state is spending enormous amounts of money on housing benefit, and there are too many people living in properties with empty bedrooms at a time when others are subject to overcrowding.

The average claimant will see their housing benefit cut by £14 per week. A minority – about 7 per cent of people – will face a cut of £31, according to Department of Work and Pensions (DWP) analysis.

Social housing tenants will then have a choice: take the hit or move to a smaller property. Either way, the government achieves one of its aims of reducing underoccupation or the housing benefit bill.

Labour have called the policy “callous” and “perverse” while the National Housing Federation, which represents social landlords, says it is “ill-thought”, “unfair” and “incompetent”.

David Cameron defended the policy in the House of Commons, saying some of the most vulnerable groups of people will be exempt from the cut. Is he right about that?

“Pensioners are exempt.”

Quite right. The changes only apply to working-age claimants. And couples with only one partner over the state pension credit age will both be exempt.

Various other groups including the husbands and wives of armed forces personnel, and homeless people in temporary accommodation, are also exempt. For more details see this DWP factsheet.

[Update: It's taken us a little while to confirm this point with DWP, but as some readers have said, new claims made by couples where both haven't reached pension credit age will NOT be exempt from the "bedroom tax" AFTER the roll-out of Universal Credit, that is from October this year.

Couples already claiming housing benefit will not be affected now, or when Universal Credit begins, even if one partner is below pension age.

Many thanks to readers who spotted this.]

“People with severely disabled children are exempt.”

No. There’s no automatic exemption for disabled children.

In fact, not only is the government not making this blanket exception, it is actually fighting a legal challenge on the point from 10 disabled children who argue that the rule changes amount to discrimination.

Under the new rules, the full benefit will only be paid if under-16s of the same sex share a room, and under-10s will have to share regardless of gender. And the expectation is that this will apply to disabled youngsters too.

But local councils will have the discretion to waive the cut in regard to some disabled households. And there is a £30m hardship fund, the money targeted at preventing people whose homes have been adapted to help them cope with disability from being forced to move.

We don’t have much more detail on exactly what guidance has been issued to local authorities on who they spare from the cut, or how many disabled children are likely to be affected.

And the £30m has to be seen in the context of the total benefits cut disabled people are expected to take.

According to government impact assessments, 420,000 of the 660,000 people affected by the changes are disabled, and they will lose an average of £14 a week. That’s just under £306m a year.

So there is some money available and councils are expected to use some discretion, perhaps mitigating the impact for the most severely disabled, but there is no “exemption” for disabled children overall.

“People who need round-the-clock care are exempt.”

Wrong again. DWP has said that an extra bedroom is allowed if a disabled person has a live-in or overnight carer. But that doesn’t apply if the carer is also your partner or spouse.

If you are disabled and your wife is also your full-time carer, but needs to sleep in a different room, you will still face a benefit cut.

Again, you could be eligible for money from the hardship fund, but that doesn’t amount to an exemption to everyone who needs 24-hour care.

“We are spending £23bn on housing benefit. That is up by 50 per cent over the last decade.”

True. DWP spending tables show that we were spending just over £16bn in real terms in 2002/3 and will spend £23.8bn this year. That’s a rise of 48 per cent in ten years.

The verdict

The Prime Minister didn’t get it all wrong today. He was right on the scale of increases in housing benefit over the last decade. And he was right to point out that there are important exemptions from the changes, including pensioners.

But, while there are measures in place that are intended to protect disabled people, it’s wrong to suggest that severely disabled children or people who need round-the-clock care will definitely not be affected.

By Patrick Worrall