08:20 Dec 22, 2011 

Having considered Donna's input, perhaps a better option might be: "who has asserted jurisdiction, when his/her jurisdiction is concurrent with that of another judge". A bit wordy though.

22:58 Dec 21, 2011 

The EN civil law term prevention does exist - the right of a judge to take cognizance of an action over which he has concurrent jurisdiction with another judge - Blacks Law Dictionary, but is unlikely to be understood even by US or GB lawyers, which is why I suggest assert, i.e. one judge asserts his/her right in relation to another judge's concurrent jurisdiction.