JAR-FCL 1.110
(a) - Privileges [of a PPL] Subject to any other conditions specified in JARs, the privileges of the holder of a PPL(A) are to act, but not for remuneration, as pilot-in-command or co-pilot of any aeroplane engaged in non-revenue flights.
To exercise the privileges of a PPL (or the private privileges of a CPL (JAR-FCL 1.150(a)(1))or ATPL (JAR 1.275(a)(1))), you need to hold only a Class 2 medical (JAR-FCL 1.105).
The requirements for a multi-pilot type rating are at JAR-FCL 1.250.