Media playback is unsupported on your device Media caption David Davies talks to teenager Amy Evans and her partner Lloyd Mulry and suggests she moves back to her mother's home

Changes to housing benefits - the so-called bedroom tax - are not working as well in Wales as other parts of the UK, says a senior Conservative MP.

David Davies, on a visit to Blaenavon, Torfaen, blamed a shortage of smaller properties for people on benefits to move into compared to large cities.

The reforms see housing association and council tenants having benefits cut if they are deemed to have spare bedrooms.

Since April it has meant a 14% cut for one spare room and 25% for two.

Mr Davies is chairman of the UK Parliament's Welsh Affairs Select Committee which is looking at how the changes are working in Wales.

The government have brought this in because we are in a terrible financial situation - absolutely unbelievable David Davies

The committee is due to publish its own report on the changes shortly.

Monmouth MP Mr Davies said: "These reforms are not working as well in Wales as in London or Birmingham where there is a larger stock of smaller properties."

He was speaking as the BBC Wales Week in Week Out programme went behind the scenes with Bron Afon Housing Association, which has 509 properties in Blaenavon but only 23 one-bedroom flats.

A third of the larger homes are under-occupied and affected by the benefit changes.

Mr Davies met residents in the town as part of Tuesday's programme.

He said ministers should be up front that some people would lose out from the UK government changes when they did not deserve to.

One woman is losing £21 a week due to the changes and now faces having to leave Blaenavon where her family has lived for generations.

Gail Harris has rented the same three-bedroom house for 25 years and now faces the prospect of having to leave the town if she cannot find a smaller property.

She has more than £400 arrears and said the changes were "really cruel".

Mr Davies told the 59-year-old he was "sorry" that she may be one of the people who could lose out.

Image caption Gail Harris said the changes were 'really cruel'

"There has to be a recognition - and ministers may be reluctant to do this - when you change the law there are unforeseen and unfortunate consequences," he told her.

"In other words there are some people who will lose out who don't deserve to lose out - and I believe you could be one of those and I am really sorry for that."

He added: "That doesn't mean we can reverse the whole thing or change it, because there is a wider issue.

"With limited housing stock and very limited money you can't have a situation where large numbers of people are under occupying - people living on their own in social housing with two or three bedrooms.

"That situation couldn't be allowed to continue."

Mr Davies also provoked anger when he spoke to a young couple.

"You are not going to like what I have to say to you," he told 17-year-old Amy Evans and her partner Lloyd Mulry.

Media playback is unsupported on your device Media caption There are no options to move into smaller properties in parts of Wales, it is claimed

"The government have brought this in because we are in a terrible financial situation - absolutely unbelievable.

"And the days when we were able to fund people in your situation are gone."

He told Amy he would move back home if he was in their position and that Lloyd should leave Wales for somewhere like London if he could not find work in Blaenavon.

Housing officer Claire Dullea told the programme she could see why the legislation had been introduced.

But she added: "If we haven't got those one bedrooms available for people to be able to move into then it's not going to happen - and those people left in the three-bedroom houses paying the bedroom tax are really, really struggling."

Week In Week Out is on BBC One Wales, Tuesday 8 October at 22:35 BST.