The procedure governing litigation in the civil court is contained within the Civil Procedure Rules or CPR as they are commonly known as.
CPR 55 (Possession Claims) are the specific rules governing claims for possession of land.
Court fees have to be paid for the issuing of a clam form. A list of civil court fees is contained on leaflet EX50.
The power of the court to grant possession of land is contained within CPR 55.
Under CPR 44.2 (2) the general rule is that the unsuccessful party will be ordered to pay the costs of the successful party. However the court may make a different order. The court has discretion as to whether costs are payable by one party to another, the amount of those costs and when they are to be paid.
A copy of the CPR can be found here.