Apparently they're legally obligated to consider it if they get over 100,000 signatures - they have way more.
True.
Any petition to the Crown which gains more than 100,000 signatures MUST be debated in Parliament within 6 weeks of the petition being received, irrespective of it's merits, and the results of the debate presented to Her Majesty for due consideration. Failure to do so, except in time of war, is one of the few automatic triggers for dissolving Parliament and holding a general election.
It's why they debated banning Trump, remember? Got over 100,000 signatures.