Does a plaintiff have an obligation to mitigate damages against another party?

The obligation to mitigate damage may not include commencing proceedings against another even where there may be a prima facie right to the relief sought: Ought the plaintiff as a reasonable man to enter on the litigation suggested? It was agreed that the defendant must offer him an indemnity against the costs, and it was suggested on the defendant’s behalf that (i) if an adequate indemnity were offered, (ii) if the proposed defendant appeared to be solvent, and (iii) if there was a good prima facie right of action against that person, it was the duty of the injured party to embark on litigation to mitigate the damage suffered. This is a proposition which, in such general terms, I am not prepared to accept, nor do I think I ought to entertain it here, because I am by no means certain that the foundations for it exist. ... Pilkington v. Wood, [1953] 2 All E.R. 810 at 813.