we experienced this very situation in 2004, we took it all the way to tribunal, 25% of our award went on legal fees but the pay out was still good. Making some one redundant in maternity leave is legal, believe it or not but we proved that it was a constructive dismissal etc. Phone solicitor that does employment law. They will usually talk through details by phone and will be interested because usually the case is clear cut. Citizens advice also do local free advice one evening a week, phone and make an appointment. good luck