The Coronavirus Act 2020 was updated on the 28th August 2020, just in time for any fun events over the August Bank Holiday and also in time to arrest Piers Corbyn at the really well-attended Unite For Freedom rally at Trafalgar Square, London on the 29th August.
Essentially (without any scrutiny by our MPs) it has now been declared forbidden for anyone in England to organise and/or facilitate public gatherings (inside or outside) of groups of 30 people or more. Any person found doing so (organising/facilitating) can be liable for up to a £10,000 FPN (fixed penalty notice), plus having any equipment removed and premises shut down by the police - or if the person chooses not to accept the FPN, then they could be liable for criminal prosecution.
That's what I understand from what I've read. For the details, please see the following link: