trial. By its nature, however, preventive detention is a precautionary measure and involves making decisions on limited information to prevent threats to national security from materializing. Jayakumar said that the court is ill-equipped to determine whether there are suspicious circumstances which justify pre-emptive action. Tham agrees with this view, but argues that it applies only where the courts review the exercise of executive power. He distinguishes the objective test applied in Chng Suan Tze from the situation mentioned by Jayakumar, since the court is only interested in whether there is a national security issue involved. Thio Li-ann has opined that the 1989 measures taken to limit judicial checks on executive power demonstrate a preference for non-legal institutional checks. One example of a non-legal institutional check is the requirement under the Constitution and the ISA for an advisory board to hear detainees' representations and recommend to the President whether a detention order should be terminated. Thio argues that such checks are weak and cannot replace judicial review. She contends that since Article 149 of the Constitution permits the enactment of repressive laws which contravene constitutional liberties, meaningful restraints should be placed on the wide discretionary powers under the ISA. Similarly, in Chng Suan Tze, the Court of Appeal rejected the view that the executive's accountability to Parliament is a sufficient safeguard against the arbitrary exercise of power. Eunice Chua argues against adopting the subjective test and limiting judicial review to breaches of the procedures stated in the ISA. Her argument is based on the premise that courts should consider notions of substantive democracy in performing their judicial role. Chua argues that in Teo Soh Lung the Court of Appeal should have considered whether there were sufficient safeguards for the protection of detainees after the curtailment of judicial review through constitutional and legislative amendments. She suggests that Article 151, which provides for restrictions on preventive detention, should be read liberally in favour of detainees, bearing in mind the exclusion of fundamental liberties by Article 149. In her view, the curtailment of judicial review should therefore be rejected, as it does not accord with the "spirit" of Article 151 of the Constitution which ensures safeguards for detainees. Conversely, Jayakumar argued in 1989 that judicial review is an inappropriate safeguard in preventing abuse of the detention powers under the ISA in the situation where a dishonest government is in power. He argued that judicial