What is the test for undue influence?

I begin with the matter of undue influence which has been defined as some unfair and improper conduct, some person from outside, some overreaching, some form of cheating, and generally though not always some personal advantage obtained by (the guilty party).” Allcard v. Skinner (1887), 36 ch. D. 145. No matter how often or intensively I review the evidence, I cannot be persuaded that there was any endue influence exerted by the respondent. Any physical abuse or actual physical domination had ceased several months prior to the execution of the agreement. In fact, the applicant described her relationship with the despondent subsequent to the separation is being “good”. While It is correct that the applicant underwent surgery during the period of separation I cannot accept that this placed her in such weakened condition that she came under the domination of the respondent, particularly when the operation was two months prior to the signing of the agreement.