Brexit negotiations will take longer than two years, Simon Fraser says

The future relationship between the UK and the EU will not be negotiated within two years, according to the former head of the Foreign Office.

Separation talks could be done within the two year deadline set out in Article 50, but a future relationship would take longer to negotiate, Sir Simon Fraser told BBC Newsnight.

Sir Simon said transitional arrangements would therefore be necessary.

Prime Minister Theresa May will invoke Article 50 on Wednesday.