If you mean at the mediation appointment, you offer £0 to settle and do not discuss your defence, it will be over in a few minutes. Search this forum for lots of examples.
If you mean after that, the case will be allocated to a court local to you, note the date by which the claimant has to pay the court fee because the case will be discontinued rather than paying the fee.
Their tactics are either to scare people into paying up or, if they ignore the court paperwork, to secure a judgment in default. They give up rather than incur the cost of court for anyone who properly defends their case.