Labour Relations Act. Under the law, a person must obey each of the following rules: He/she must picket "peacefully and without causing an obstruction.'' He/she can only picket as part of a labour dispute in which a strike or a lockout has been lawfully declared.

He/she must picket "at or adjacent to the premises in relation to which the labour dispute exists.'' He/she must be "ordinarily engaged in the trade or industry in which the dispute occurs.'' He/she must be a member of a union which is a party to the dispute, and must carry written authorisation from a union officer to picket on behalf of the union.

He/she must produce the written authorisation for inspection if requested to do so by any Police officer.

No more than 10 people can normally picket at the premises concerned. The law makes some limited exceptions in cases where several unions are involved in the same dispute.