MSP blasted Tory welfare tsar Iain Duncan Smith yesterday after new research showed that his regime had hit Scotland’s poorest up to five times harder than its richest.

Backbenchers on Holyrood’s welfare reform committee called on the Work and Pensions Secretary to account for a study of Scottish electoral wards which found people in some of the poorest areas lost nearly five times as much under his welfare reforms as those in more affluent areas.

Yet Mr Duncan Smith’s office appeared to rebuff the renewed calls for accountability.