The UK Police recently said it was illegal to support Palestine at upcoming protest. They said pro Palestine protests are linked to a UK group called Palestine Action which seeks to end Israeli control over Palestine and has been labeled a terrorist group.

https://time.com/7307480/palestine-action-protest-united-kingdom-london-police-arrests/

A protest took place for it to be legal to support Palestine. British police arrested over 500 people for supporting Palestine under terrorism laws.
The British Government supports the decision.

https://www.msn.com/en-gb/news/world/home-secretary-defends-arrest-of-more-than-500-people-at-palestine-action-protests/ar-AA1KiOlw?ocid=BingNewsSerp