COMPANY FORCING EMPLOYEES TO TAKE LIEU DAYS!?

company i work for are forcing people to take lieu when suits them best! and not letting us choose when to take it! we used to be able to take it when we ''NEEDED'' it but aparently if it went to tribunal, we wouldnt not win! could some1 tell me if we have a right to choose when we take our lieu days or company can just ''make us'' take them, when suits them best?