The Social Security (Netherlands) Order (Northern Ireland) 2007

(2) If any dispute cannot be resolved as in paragraph (1) it shall be submitted, at the request of the competent authority of either Party, to an arbitration tribunal which shall be constituted in the following manner:

(a) each Party shall appoint an arbitrator within one month from receipt of the demand for arbitration. The two arbitrators shall appoint a third arbitrator, who shall not be a national of either Party, within two months from the date on which the Party which was the last to appoint its arbitrator has notified the other Party of the appointment;

(b) if within the prescribed period either Party should fail to appoint an arbitrator, the other Party may request the President of the International Court of Justice or, in the event of his having the nationality of one of the Parties, the Vice-President or next senior judge of that Court not having the nationality of either Party, to make the appointment. A similar procedure shall be adopted at the request of either Party if the two arbitrators cannot agree on the appointment of the third arbitrator.