Complex sentence: The Scottish Labour Party is registered as an Accounting Unit (AU) of the Labour Party with the Electoral Commission and is therefore not a separately registered political party under the terms of the Political Parties, Elections and Referendums Act 2000.
Split into simpler sentences: The Scottish Labour Party is formally part of the Labour Party and is registered as an Accounting Unit (AU) with the Electoral Commission. It is not a separately registered party under the terms of the Political Parties, Elections and Referendums Act 2000.