Legal aid is not free. It is funded by tax payers and has to be repaid in certain circumstances:
A person may be asked to pay some of the costs of their case. This is means-tested.
If a person wins money or property in a civil case, they may be asked to repay some of their legal costs. This is called the statutory charge.
If they do not have the means to pay immediately, they can:
* arrange to pay it in instalments over time
* opt for the statutory charge to be placed on the property (which means the money can be reclaimed when the property is sold or becomes part of an estate after their death).
http://www.legalservices.gov.uk/public/can_i_g et_legal_aid.asp#free
And rightly so.