The opposition day debate was initiated by Labour yet 47 Labour MPs, including 10 Scottish Labour MPs and Midlothian's David Hamilton, failed to turn up for a vote that was lost by just 26 votes.
SNP spokesperson for Work and Pensions Dr Eilidh Whiteford MP said:
“Today we could have been talking about how the Bedroom Tax has been scrapped, but instead the question on the minds of many Scots is- where were they? Labour MPs need to explain their absence.
“Some may have very good reasons for missing the vote, but there can be no excuse for a quarter of Scotland's Labour MPs not turning up for a vote to scrap the Bedroom Tax that could have been won.
"It is now clearer than ever before that only with a Yes vote will we finally be able to get rid of the unjust bedroom tax and have a welfare state that reflects the views and votes of the people of Scotland."