After the United Kingdom voted to leave the European Union in the June 2016 referendum, Marx posited in an interview with "The Daily Telegraph" that Brexit was an opportunity to improve safety standards in the NHS by strengthening medical device legislation and language testing for non-British workers. She felt the European Working Time Directive which restricts working hours in the NHS needed to be relaxed to enable more hours of training. The Royal College of Surgeons of England later sent out a press release clarifying that they did not endorse a return to excessive hours for NHS workers.