Hi Sharon,
Are you sure that you are solely on Income Related ESA? If you had worked for a few years prior to becoming sick I would have expected you to be on Contributory ESA, even if you were getting an income-related top-up.
If you
are solely on IR ESA then I'm afraid you will lose this if your partner works for more than 24 hours a week
24 hour work rule for ESA(IR) If you are on part Contributory with an IR top-up then you would lose the top-up but not the contributory element.
I hope I have explained this clearly. If not, please feel free to reply to this message and we will do our best to help