An employee has no right to complain of unfair dismissal if at the time of dismissal he was taking part in an unofficial strike or other unofficial industrial action.
Subsection (1) does not apply to the dismissal of the employee if it is shown that the reason (or, if more than one, the principal reason) for the dismissal or, in a redundancy case, for selecting the employee for dismissal was one of those specified in or under—.
A strike or other industrial action is unofficial in relation to an employee unless—
The provisions of section 20(2) apply for the purpose of determining whether industrial action is to be taken to have been authorised or endorsed by a trade union.
The question whether industrial action is to be so taken in any case shall be determined by reference to the facts as at the time of dismissal.
In this section the "time of dismissal" means—
and a "working day" means any day which is not a Saturday or Sunday, Christmas Day, Good Friday or a bank holiday under the Banking and Financial Dealings Act 1971.
For the purposes of this section membership of a trade union for purposes unconnected with the employment in question shall be disregarded; but an employee who was a member of a trade union when he began to take part in industrial action shall continue to be treated as a member for the purpose of determining whether that action is unofficial in relation to him or another notwithstanding that he may in fact have ceased to be a member.