HM Revenue and Customs has appointed a new general counsel, taking on the legal director of the Department for Environment, Food and Rural Affairs (Defra).

Alan Evans will take on the top legal role at HMRC on 1 January 2019, advising on all aspects of tax law and leading its litigation team. He will also be a member of the tax agency’s executive committee.

Evans has built up a legal career spanning 30 years, including his former role as legal director at Defra, as well as stints as legal adviser to the Cabinet Officer and the European Commission.

Evans’ appointment was formally ratified by the Prime Minister Theresa May, following an “extensive” internal and external search.

Evans succeeds Gill Aitken, who stepped down in June to become registrar at the University of Oxford. Mid-June, David Bunting, a former legal director at HMRC and part of the UK Government-wide Border Delivery Group. filled the role on an interim basis while HMRC carried out an open recruitment process for a permanent replacement.

Aitken joined HMRC in 2014 to lead the Solicitor’s Office and legal services, advising HMRC and HM Treasury on all aspects of tax law and leading a large litigation practice safeguarding tax revenues.

HMRC’s chief executive Jon Thompson said he was “delighted” to welcome Evans “at a critical time for the department”. It is currently carrying out wide-ranging preparations for Brexit, including work to ensure it is ready handle the extra customs demands that will be needed in the event of a no-deal departure from the EU.