The Tories maintain it is needed to free up homes for people in overcrowded housing, yet only 7% of those affected have been able to move to a smaller home.
This is mainly because there are not enough smaller homes to accommodate the numbers and the process would take 10 years.
To speed it up would mean housing associations building lots more one bedroom flats, meaning fewer new two and three bedroom homes built for families.
The other reason given is it's fairer because the same policy was introduced for private sector tenants.
This ignores the huge differences between the social housing sector and the private rented sector.
Firstly the profit margin from the cash in private rent is going to the landlord, mostly individuals looking after an investment and swelling their bank balance or retirement fund.
In the social sector, housing associations are increasingly involved in community improvement projects.
Cash from rents is invested in environmental improvements, energy saving schemes, crime reduction measure and even job creation programmes.
Ask private sector landlords how many are investing in similar initiatives and not stashing it in an ISA.
There is another significant difference between those occupying social housing and those in the private rented sector.
The turnover of tenants is far greater in the private sector, with many in private lets looking to get on to the property ladder or moving from one location to another for work or education.
In the social sector, more people are putting down roots and living in the same community they were brought up in and have a social investment as well as a personal attachment to the community.
MORE than half of all private tenants have been at their address for less than one year and only 20% for more than five years.
In social housing only 17% have been there for less than a year and 62% have been in the same home for more than five years.
The number of people in social housing has fallen in the last decade from 32% to 23% while private renting has gone up from 5% to 11%,
Reasons include right to buy reducing available housing stock and larger mortgage deposit requirements keeping people out of home ownership for longer.
Social landlords have a very different purpose and ethos from those in the private sector. They should not be treated the same and the bedroom tax is damaging stable communities.
Tory MSP Alex Johnstone said the £42m saved by the bedroom tax was a "bonus for the tax payer".
That's £42m taken from social housing, working class communities and ordinary people trying to make ends meet. That's not a bonus, that's shameful