hi i recently rented out my property (assured shorthold tenency agreement) for a term of 6 months.After the term the tenent will have a statutory tenency on the same condition which can end by 2 month's notice.the tenency stated on 12th jan 2008.but today i notice the same property is adverticed for to let (sub let) by the the same estate agent i rented the house without my knowledge.on the tenency agrement the part for sub let is like this for the first three month's of this agreement not to assign sublet part with or share possession of the property or any part of it nor to take in lodgers so that at all times the property remains in the exclusive occupation of the tenant .After the six months of this agreement the tenent may sublet or assign this tenency but only with the lanlords prior written consent which shall not be unresonably withheld. I donnt want the tentant to sublet my property.Are they allowed to do sub let based on my contract.If not want action I can take againt the estate agent and tenent.please help