"Mabel,he's done it again. He's just made his 29th application to get that judgment cancelled."
Some persistent litigants will never give up and will make unmeritorious application after unmeritorious application. That could cause you untold aggravation and expense. The most efficient way to stop them (which is separate from seeking to have them declared a vexatious litigant) is to secure from the court a civil restraint order. The more troublesome they have been the more severe will be the terms of the restraint order. At the least, that will prevent them from making another application in particular proceedings without the prior consent of a judge.
Civil restraint orders (see Breaking Law at chapter 15) are available in civil proceedings in the county court and High Court and family proceedings in the Family Court. From next Thursday 6 April 2016 a civil restraint order will be available in cases in the Court of Protection which deals with the affairs of those who lack the mental capacity to deal with them themselves and deciding disputes over powers of attorney, is just one of its functions. The power to make a civil restraint order is introduced by the Court of Protection (Amendment) Rules 2017 SI 2017/187 and there is a new Practice Direction 23C covering the topic. The rules also introduce a new framework for international applications.