Thanks guys for your hints. Germany won't accept partial training, official statement from LBA quotes JAR-FCL German version 1.065 (a), where it says that initial medical, training and exam must be completed within the country that is issuing the license. It also might mean (and I am sure it does!), that if one begins his flight training in Germany, and since it will be based on JAR-FCL German version, he "must" complete the training and exams in Germany, otherwise it's invalid - what an elegant lock-in
Looks like if I decide to do the theory in the UK, I have to target full UK CPL flight training program as well. MEP and IR can be done anywhere.
Cheers