I must say this is one time when I don't think such a danger actually exists, and the reason is by the way it's worded here; it says, “for the purposes—of this Standing Order”, which I assume means for the purposes of this section. Maybe it should say “this section”, which would be section 31.1, which deals only with a caveat on an earlier section, “members of political parties not officially recognized in the House are not considered independent members”. So it's just for the purposes of section 31.1.
I think by putting the caveat in that way, it makes it very clear it doesn't relate to the concern. It doesn't actually cause the harm that Ms. May legitimately raised. I think it's quite clear that there's no danger of members—I assume she's worried that, say, a Green Party caucus of seven or eight members would be denied the right to pool their questions or give them to their leader.