Instead of arguing amongst ourselves just read the
gov.uk facts
Dismissal for industrial action
You can’t be dismissed for industrial action if:
it’s called as a result of a properly organised ballot
it’s about a trade dispute between workers and their employer (eg about your terms and conditions)
a detailed notice about the industrial action (which is legally required) has been given to the employer at least 7 days before it begins
You can claim unfair dismissal at an employment tribunal if you’re dismissed for taking industrial action at any time within the 12 weeks after the action began.
After 12 weeks, you can be dismissed if you take industrial action and your employer has tried to settle the dispute. For example, your employer may bring in advisers from Acas to help find a solution.