Part III Rights in relation to union membership and activities
Contracts for supply of goods or services
144 Union membership requirement in contract for goods or services void.
A term or condition of a contract for the supply of goods or services is void in so far as it purports to require that the whole, or some part, of the work done for the purposes of the contract is done only by persons who are, or are not, members of trade unions or of a particular trade union.