law: Arbitration Act 1940
  Section 12
  Grounds for Challenge.
  (1) When a person is approached in connection
  
  with his possible appointment as an arbitrator, he shall disclose in writing
  
  any circumstances likely to give rise to justifiable doubts as to his
  
  independence or impartiality.
  (2) An arbitrator, from the time of his
  
  appointment and throughout the arbitral proceedings, shall, without delay,
  
  disclose to the parties in writing any circumstances referred to in sub-section
  
  (1) unless they have already been informed of them by him.
  (3) An arbitrator may be challenged only if -
  (a)  circumstances 
  
  exist that give rise to justifiable doubts as to his independence or
  
  impartiality, or
  (b)  he 
  
  does not possess the qualifications agreed to by the parties.
  (4) A party may challenge an arbitrator
  
  appointed by him, or in whose appointment he has participated, only for reasons
  
  of which he becomes aware after the appointment has been made.