The ACAS Arbitration Scheme (Great Britain) Order 2004

XXVI. LOSS OF RIGHT TO OBJECT

214.  If a party to arbitral proceedings under this Scheme takes part, or continues to take part, in the proceedings without making, either forthwith or within such time as is allowed by the arbitrator or by any provision in this Scheme, any objection:

(i) in an English/Welsh arbitration, that the arbitrator lacks substantive jurisdiction as defined in paragraph 187EW, or in a Scottish arbitration that the arbitrator lacks substantive jurisdiction as defined in paragraph 191S, aside from any jurisdictional objection with respect to the circumstances of the dismissal, which will be waived in any event, as set out in paragraphs 21 to 23 above,

(ii) that the proceedings have been improperly conducted,

(iii) that there has been a failure to comply with the Arbitration Agreement or any provision of this Scheme, or

(iv) that there has been any other irregularity affecting the arbitrator or the proceedings,

he or she may not raise that objection later, before the arbitrator or the court, unless he or she shows that, at the time he or she took part or continued to take part in the proceedings, he or she did not know and could not with reasonable diligence have discovered the grounds for the objection.