The defence secretary, Ben Wallace, has urged the Conservative peer and former minister Greg Barker to quit his lucrative role on the board of the Russian aluminium firm EN+, whose owners include the oligarch Oleg Deripaska.
Lord Barker, an energy minister in David Cameron’s government, earned $4m last year as executive chair of the firm, and devised a plan to help the company respond to US government sanctions levelled against the company and Deripaska in 2018.