Sir Tim Barrow has been appointed the UK's new ambassador to the EU, replacing Sir Ivan Rogers, according to the BBC.
Downing Street described the former ambassador to Moscow, who will now play a key role in the UK's Brexit talks, as a "seasoned and tough negotiator," reports Unian.
Sir Ivan's exit, which came earlier than planned, sparked a row with his resignation note criticizing "muddled thinking" from ministers.
Some MPs had accused him of being "half-hearted" towards Brexit. Critics of the outgoing ambassador were accused of trying to "politicize" the civil service, with a trade union saying there was a "deafening silence" from ministers in defending officials' independence.
Sir Tim was the UK's ambassador to Moscow from 2011 to 2015. He previously served in the Foreign and Commonwealth Office, as a representative to various bodies of the European Union. He joined the Foreign and Commonwealth Office (FCO) in 1986 and served as a desk officer on the Western European Department between 1987 and 1988. Also served as British Ambassador to Ukraine in 2006–2008.