Sarah
Your partner cannot make a new claim for ESA but providing you are not claiming New Style ESA, you can ask to be financially assessed for Income Related ESA. ESA(IR) is dependant on your household income, your savings and assets, and any hours that your partner works. See
Asset and savings rule for ESA(IR) 24 hour work rule for ESA(IR) Your ESA(CB) will continue to be paid but will be deducted from any EA(IR) that you are entitled to.
Gordon