Parties to civil proceedings in England:
Up to 1999: plaintiff and defendant
(divorce: petitioner and respondent)
A claimant included a person claiming some benefit, for instance unemployment benefit.

From 1999 (Civil Procedure Rules)
claimant and defendant
(divorce: petitioner and respondent)
A claimant for unemployment benefit etc. (as before)

In Scotland: pursuer and defender
(divorce: petitioner and respondent)
Benefit claimant as above

Most English websites mention ‘claimant (plaintiff)’ – after all, it’s only been seven years since the change. A Google search for claimant -plaintiff site:uk produces mainly references to benefit claimants.

Here’s an exception: the claimant user guide of Her Majesty’s Courts Service.

I have previously linked to Michael Quinion on this subject. He writes of legal Latin being ‘swept away’, which seems a bit sweeping, so to speak.

I mention this because I don’t often use the word claimant to translate Kläger(in). My translations don’t just go to England, either. Do people who translate for England and the rest of the UK use claimant? Do translators for the EU and the European Court of Justice? I think maybe only sometimes. And I remember in 2000 or 2001 asking a British publisher client whether I was now to use claimant, and getting the answer ‘When it’s appropriate’, which suggested to me that the problem hadn’t even filtered through.