It depends on whether the strike was a form of 'protected industrial action'. Although a strike, or other form of industrial action, is a breach of the contract of employment, which would normally give the employer the right to terminate, dismissal would be unfair if the action was 'protected'.
This would be the case where the action had been called lawfully, i.e. there had been a secret postal ballot, notice given to the employer, the balloting threshold was met, etc.; and where the strike is over a work dispute with your own employer. Workers who take 'unofficial' industrial action or engage in 'wildcat' strikes are not protected from dismissal. Check with your union if you are concerned at all about the legality of your planned industrial action.
Dismissal of employees engaged in protected industrial action is unfair:
- during the first 12 weeks of the lawful industrial action;
- if the employee stopped taking part in the industrial action during the 12-week period and is later dismissed for taking part in the action during that 12-week period; or
- after 12 weeks from the start of the action, where the employer has not reasonably attempted to use a procedure (for example, collective conciliation through Acas) for settling the dispute.
If employees are locked out (i.e. prevented from returning to work) during the 12-week period, it will be extended (by one day for every day that the employee was locked out).