A lesbian couple have filed a lawsuit against their doctors alleging that cancer treatments damaged their sex life.

The case is a first under Connecticut’s civil union legislation and if Margaret Mueller and Charlotte Stacey are successful it would be the first time a gay partner has sought compensation for medical malpractice in the state.

Two doctors are being sued for giving Ms Mueller the wrong type of treatment thinking she had ovarian cancer when the couple claim she really she had cancer of the appendix.

The doctors claim the cancer had spread after chemotherapy.

Lawyer for the couple, Joshua Koskoff said: “I think it’s any patient’s worst fear that everything they’re doing to treat themselves is for naught.”

The couple had a civil union last November after 21 years as domestic partners.