You will have to renew at least one of your class ratings, by LPC. (Although your FI is current, if you haven't flown in two years your SEP will not be) In order to do this, I believe you will have to apply to a UK Head of Training to assess whether a training minimum is required before that LPC.
The UK CAA will not issue an EASA licence without at least one class rating being valid, in addition to some other requirements. Any expired ratings will go on the "back" of your new licence when issued.