Here is what I got from the first page of results to a general search about current/planned strikes, I'm sure there are more, and if anyone knows of any others, please do link info and I'll edit them in:
https://www.pcs.org.uk/news-events/news/british-council-workers-due-strike-week
https://www.wealden.gov.uk/waste-industrial-action/
https://www.leeds-live.co.uk/news/uk-world-news/ryanair-strike-2022-staff-confirm-24213578