Electoral Reform Act 2022
Political groups
48. Where a party which is registered in the Register of Political Parties as a party organised to contest a European election, or which applies for such registration in the Register of Political Parties, informs the Registrar that a member of the party, being a representative in the European Parliament (whether by reason of that member having been elected as such a representative in the State or having been nominated as a replacement candidate under the Second Schedule to the Act of 1997), is a member of—
(a) a political group formed in accordance with the rules of procedure of the European Parliament, or
(b) a European political party,
the Registrar shall, if the member certifies in writing to the Registrar that he or she is a member of that party and that political group or European political party, note on the Register of Political Parties, in relation to the party, the name of that political group or European political party.