100. A person shall not be regarded as having been elected to the Parliament pursuant to this Part if the person is, for the time being—

(a) a representative in the Parliament,

(b) not eligible for election under this Act to the Parliament,

(c) a person who, by virtue of any provision laid down under the treaties, is not entitled to assume the office of representative in the Parliament,

(d) not willing to assume such office, or

(e) in case—

(i) the vacancy concerned is not one to which rule 97 applies, and

(ii) the relevant representative elected under this Act to the Parliament at the last preceding European election was at that election a candidate of a registered political party,

a person who is not a member of that party.