Joint ESA claim

I would be grateful for help on the following, please.  I have checked in CPAG and Advisernet and reached the conclusion that the following couple could either claim ESA or JSA.  The client receives ESA and has moved in with partner, who does not have LCW and has not been claiming anything (ex-student).  As a couple either the ESA claimant could claim ESA for the 2 of them or the potential JSA claimant could claim JSA for them both.  For the JSA claim, the partner who has LCW would not have to fulfil the JSA requirements, but I cannot find the reverse for ESA - ie, would the partner of the ESA claimant have to be available for and actively seeking work? I feel that this would be the case, as it will be under UC claimant commitment rules, but cannot find it anywhere.  Does anyone know?