No, says the EAT in Mr Clutch Auto Centres v Blakemore.
In this case the principal dispute between the parties was whether the employee had resigned on 18th October 2012 (as the employer contended), or whether he had been summarily dismissed on 6th November 2012 (as he himself contended). Both parties therefore accepted that the employment relationship had come to an end, and on the employee's case this must have happened by 6th November 2012 at the latest. At first instance the employment tribunal rejected both parties' contentions, and found as a fact that the employment relationship continued.
The employer appealed to the EAT (HHJ Peter Clark presiding). The appeal was allowed, with the EAT accepting that the employment relationship had ended by virtue of the employee's election to institute proceedings on the basis of a dismissal he alleged had been effective on 6th November 2012. He would not be permitted to resile from that position.
Essentially this means that an employment tribunal may not determine issues which are not in dispute between the parties. Going further, HHJ Peter Clark suggested that an employment tribunal should not even go as far as to express an opinion on matters not in dispute.