When Tony Blair intervened to get the Serious Fraud Office investigation into BAE's alleged corruption in Saudi Arabia stopped on grounds of national security, few people believed a legal challenge could succeed. When it comes to protecting the lives and security of the nation, the courts allow the executive "an especially wide margin of discretion", noted the judges in this case. Yesterday's judgment that the SFO director acted unlawfully in dropping the inquiry is therefore a major blow to the government - and its ability to sweep controversial issues under the carpet.
The ruling has seriously constrained the government's ability to invoke national security without scrutiny. The courts have increasingly been standing up to the government in relation to terrorism cases and slowly staking out the limits to its powers. But a challenge to a decision to quash a prosecution on national security grounds through a judicial review is unprecedented.
The high court has made clear that national security arguments cannot be used to override the rule of law. "It is obvious," it says, "that the decision to halt the investigation suited the objectives of the executive. Stopping the investigation avoided uncomfortable consequences, both commercial and diplomatic." The judges in effect accused the government of abusing national security arguments as a cloak for other more cynical motives.
Just two weeks before the judgment was delivered, the government mounted an attempt to preserve its powers. In a breathtakingly cynical move, it introduced draft legislation creating a power for the attorney general to halt prosecutions on national security. The bill concentrates power for making such decisions in the hands of the executive and makes a judicial review of a decision virtually impossible.
Under the proposed law, the attorney general will not have to provide information to parliament that impacts on national security or international relations. If anyone questions that decision, the attorney general will merely have to get a minister to provide a certificate stating it is to be considered "conclusive evidence of act".
One of Gordon Brown's first acts on taking over from Blair was to launch a major series of consultations on constitutional renewal. It was seen as an attempt to distance himself from what were regarded as the worst excesses of Blair's rule. By letting these new powers for the attorney slip into the draft bill, Gordon Brown has shown himself to be no different to his predecessor.
Giving in to Saudi demands to drop the SFO inquiry looks grubby and self-serving, and has damaged Britain's reputation irreparably. The decision can only have given succour to those corrupt regimes whom Britain repeatedly lectures on cleaning up their act.
Last week the OECD visited the UK, in a form of visit reserved for those countries deemed not to be complying with its anti-bribery convention. That is a damning reflection on the government. But yesterday's judgment also offers an opportunity: it could decide it is serious about standing up for the integrity of the justice system and the independence of its prosecutors. It could decide to accept proper scrutiny of its national security decisions. It could decide that it means business on enforcing its corruption laws regardless of threats, regardless of who is accused, and regardless of who it upsets. Let us hope so.
Eric Avebury, a Liberal Democrat spokesman on foreign affairs and vice-chair of the parliamentary human rights group and Susan Hawley, an analyst for The Corner House, an anti-corruption campaign group.