What is the legal test for a solicitor who acts for both the donor and the donee?

In some early English decisions an important point to note in the requirement of independent advice is that a solicitor who acts for both the donor and the donee was not seen to be an independent adviser. For example, in Powell v. Powell, [1900] 1 Ch. 243, Farwell J. states at pp. 246-47: Further, in my judgment, the donee does not discharge this burden by shewing that his own solicitor acted for both parties. A solicitor who accepts such a post puts himself in a false position; if he acts for both, he owes a duty to both, to do the best that he can for both. But the court requires that the donor should be placed in as good a position as if he were in fact emancipated. The solicitor, therefore, must be independent of the donee in fact, and not merely in name, and this he cannot be if he is solicitor for both. Again, his duty is to protect the donor against himself, and not merely against the personal influence of the donee, in the particular transaction.