With difficulty. It is your responsibility to ensure that they do not breach the Working Time Regulations, and a recent case at the European Court of Justice has emphasized that this is a positive rather than a negative duty - ie you must ensure that your workers take rest breaks, and not just that they can if they want to. You should at the least get them to do time sheets - which are checked - and look out for obvious signs of an inability to switch off (such as e-mails sent out in the middle of the night). Alternatively, you may wish to agree with the employee that the 48-hour limit does not apply (although you may then have to keep more extensive records of working time, and ensure that no employee exceeds 65 hours a week).
