The former Deloitte partner Carl Hughes has resigned from the board of En+, the mining company part-owned by the sanctioned Russian oligarch Oleg Deripaska, weeks after defending his decision to remain in the post following Vladimir Putin’s invasion of Ukraine. Hughes, who has served as an independent director of the London-listed company since 2019 and chairs the audit and risk committee, said last month it was his “fiduciary duty” to stay on. The members of En+ board split $7m (£5.3m) in remuneration in 2020, according to the company’s annual report published last year. His stance had placed him in opposition to British industry bodies including the Institute of Directors, which said it was “untenable” for British directors to remain on the board of Russian companies. Hughes is a former global head of energy and resources at Deloitte, and a member of the General Synod of the Church of England and deputy chairman of the finance committee of the Archbishops’ Council. He joined En+ in January 2019 on the day the US Treasury removed the company from its sanctions blacklist. En+ said at the time its removal was subject to a number of conditions negotiated with the US government, including changing the board so that it was composed of a majority of independent directors. The company, which produces aluminium and power and has 25,000 employees outside Russia, including 4,000 in Ukraine, has not been subject to sanctions following the Russian invasion. Last month, Greg Barker, the conservative peer and energy minister in David Cameron’s government, resigned as executive chairman of the board of En+, as did Joan MacNaughton, who served as an independent director of the company. En+, which owns Rusal, the biggest aluminium producer outside China, is seeking to carve its international operations out into a new company. These include bauxite mines in Guinea and a refinery in Ireland that produces a raw material for aluminium smelters across Europe. Barker has been linked with a potential senior role at the new company. “The group wishes to emphasise that the strategic review is at a preliminary stage and any future course of action will be subject to further consideration as well as discussions with the relevant regulatory bodies and key stakeholders,” the company said. On Friday, the company reported that revenues rose 36% to $14bn last year, driven by a 45% increase in the price of aluminium on the London Metal Exchange, as net profit more than tripled to $3.5bn. “It is clear that many new challenges lie ahead and we are encouraged by the strength of our resilient business and the determination of our people,” Chris Burnham, the chairman at En+, said on Friday. “Due to the tragic developments in Ukraine, we have had to temporarily halt the production at the Nikolaev alumina refinery. Our priority is to ensure the safety of all our employees there and as soon as it becomes possible to safely operate our plant there, we will immediately do so. Meanwhile, we will continue to secure stability of supply for our customers and to support our employees and their families.”