“This rule enables the court to proceed on the basis of the claimant’s unchallenged particulars of claim. There is no need to adduce evidence or for findings of fact to be made in cases where the defendant has not disputed the claimant’s allegations. That in my judgment will normally be the right approach for the court to take. Examination of the merits will usually involve unnecessary expenditure of time and resources and hence [be] contrary to the overriding objective …”