It may seem off topic but why is it necessary to have £2million of security? I have spent 3 days at the 4000 delegate SNP Conference at the SEC in Glasgow alongside the entire Scottish Cabinet, various foreign dignitaries and important guests. There were no Police on duty outside or inside the Conference centre, no obvious security personnel, no checking of bags, etc. and therefore no cost whatsoever to the public purse. There were other smaller events taking place in the centre simultaneously, with attendees for all events mixing freely in the bars and restaurants. Admission to the auditorium itself was granted on production of delegates or visitors passes, checked by party members volunteering as stewards.
I am always amazed by the tight security and police presence at the other Parties Conferences and also any occasion involving the Royals - except in Scotland where Royals (usually Princess Anne) turn up, sometimes unexpectedly to charitable events with no fuss or apparent protection whatsoever.