Well it seems to depend on who you ask.
I quote this from the website link I give below.
"According to a DVLA spokesman, qualified drivers are still entitled to drive a vehicle if their licence has expired, but what they must be aware of is that they could be charged with the offence of failing to renew their licence. If the matter went to court, then the motorist could end up with a £1,000 fine."
http://www.yourdrivinglicence.co.uk/renewing-your-photo-driving-licence-every-10-years.html