“Where’s crank-boy? ” hiding it’s civil law i don’t know enough to answer in detail.
If you get a witness summons you have to attend or you could be arrested/done for contempt.
“Right of witness to travelling expenses and compensation for loss of time
34.7
At the time of service of a witness summons the witness must be offered or paid –
(a) a sum reasonably sufficient to cover his expenses in travelling to and from the court; and
(b) such sum by way of compensation for loss of time as may be specified in Practice Direction 34A.
34(a)
If the witness summons is to be served by the court, the party issuing the summons must deposit with the court:
(1) a sum sufficient to pay for the witness’s expenses in travelling to the court and in returning to his home or place of work, and
(2) a sum in respect of the period during which earnings or benefit are lost, or such lesser sum as it may be proved that the witness will lose as a result of his attendance at court in answer to the witness summons.
3.3
The sum referred to in 3.2(2) is to be based on the sums payable to witnesses attending the Crown Court.