Croydon, like large areas of London, voted against leaving the EU, with 93,913 (54.3%) supporting continued membership of the EU and 78,221 (45.7%) wanting to leave.
After Downing Street confirmed that Mrs May and Angela Merkel have agreed to begin Brexit talks “in the next couple of weeks”, questions are likely to be raised about whether the new chief of staff is the right man to advise the Prime Minister as she negotiates Britain’s path out of the EU.
Mr Barwell, the author of a book titled ‘How to Win a Marginal Seat’, saw a majority of just 165 in his marginal seat overturned by Labour candidate Sarah Jones on Thursday night.
Ms Jones received 29,873 votes to Mr Barwell’s 24,221 – giving her a majority of 6,652.
Speaking about her decision to appoint the former housing minister to head of staff, Mrs May said: “He has been a first-class minister and is widely respected. He will bring considerable experience of the party to the post.
“As I said yesterday, I want to reflect on the election and why it did not deliver the result I hoped for.
“Gavin will have an important role to play in that. I look forward to working with him.”
Express.co.uk have contacted Mr Barwell for comment.