Britain’s departure from the European Union has raised eyebrows among scientists globally, and according to one of Sutton’s leading cancer research professors – “we are effed”.

Professor Louis Chesler, who leads a team of scientists investigating the genetic cases for cancers in children at the Institute of Cancer Research (ICR) in Sutton, is baffled by the result of last week’s referendum.

His concerns follow a letter from 150 fellows of the Royal Society – including Stephen Hawking – handed to a national newspaper that urged Britain to remain in the EU.

Last week: Sutton Councillors and MPs react to historic vote as the Borough defies London trend

Although nationally the leave campaign emerged on top last week with almost 52 per cent of the vote, Sutton’s decision for Brexit stood out against the rest of the south west London.

The majority voters in the borough came out in favour of leaving, like only five other London boroughs, by a margin of 54 per cent to 46 per cent to remain votes.

Brexit, according to Professor Chesler, will “complicate” research trials that UK scientists run collaboratively with partner groups in Europe.

He said: “Science is collaborative, it has no borders, and this is a huge loss because it will make our collaboration with EU-based scientists harder.

“It takes a long time to learn whether or not a drug is effective, and the fewer the patients the longer it takes.

“So ideally you want to test a new drug in the biggest possible patient population so that you learn quickly, and the best way to do that is run the trials in the US, the UK and the EU.

“Now, with the changes that just happened, we are effed because we have a lot of activity with the EU to make our trials bigger and now that’s going to become a lot more complicated.”

The European Union hands Britain’s scientists almost £1bn a year for research, and research units like the ICR attract talent from all over the world.

Many young scientists that work alongside Professor Chesler at the ICR campus, in Cotswold Road, and in the Royal Marsden, the institute’s partnered hospital, do not come from the UK, Professor Chesler added.

He said: “Young scientists who work in the labs and in the hospitals, many of them don’t come from the UK, we get the best people from all over the EU and this [Brexit] is going to impact that directly.

“It’s going to make it harder for academics and hospitals in the country to find qualified people to do science and medicine – that’s my personal view.

“It’s hard to track these people, you know, science is not a career where you earn a lot of money, but it does require a lot of focus and dedication in young people particularly.”