"(1) An employee who is dismissed shall be regarded … as unfairly dismissed if - (a) the reason or principal reason for the dismissal is of a prescribed kind, or (b) the dismissal takes place in prescribed circumstances. (2) In this section "prescribed" means prescribed by regulations made by the Secretary of State.
"20.
" A reason for the dismissal of an employee is a set of facts known to the employer, or it may be a set of beliefs held by him, which cause him to dismiss the employee "
"18. Pregnancy and maternity discrimination: work cases (1) … (2) A person (A) discriminates against a woman if, in the protected period in relation to a pregnancy of hers, A treats her unfavourably - (a) because of the pregnancy, or (b) because of illness suffered by her as a result of it."
"(2) If there are facts from which the court could decide, in the absence of any other explanation, that a person (A) contravened the provision concerned, the court must hold that the contravention occurred."