The United Kingdom’s ambassador to the European Union (EU), Sir Ivan Rogers, has resigned.
Sir Ivan, appointed to the job by David Cameron in 2013, had been expected to play a key role in Brexit talks expected to start within months.
According to BBC, the government said Sir Ivan had quit early so a successor could be in place before negotiations start.
Last month the BBC revealed he had privately told ministers a UK-EU trade deal might take 10 years to finalise, sparking criticism from some MPs.
He told them this was also the view of the EU’s other 27 member states.
Ministers have said a deal can be done within two years.
BBC Brussels correspondent Kevin Connolly said it appeared there had been “some failure of synchronisation” between Sir Ivan – who had been due to leave his post in November- and the UK government.
A government spokeswoman said: “Sir Ivan Rogers has resigned a few months early as UK permanent representative to the European Union.
“Sir Ivan has taken this decision now to enable a successor to be appointed before the UK invokes Article 50 by the end of March. We are grateful for his work and commitment over the last three years.”