European Commission President Jean-Claude Juncker should be investigated over claims he encouraged tax avoidance when he was leader of Luxembourg, senior Conservatives have said.
Work and Pensions Secretary Iain Duncan Smith said the commission should have “no fear of investigating their own” and urged “complete transparency”.
And Tory party chairman Grant Shapps said it was important that the commission was held to account.
Mr Juncker has denied the claims.
The government has had an acrimonious relationship with Mr Juncker since he emerged as the leading candidate to run the commission following May’s EU elections.
Mr Juncker, who took over as head of the EU’s executive body at the start of November, has come under pressure over claims that some 340 global companies were granted deals to help them avoid tax during his 18 years in office, which ended last year.