When Sinn Fein representatives start talking about their mandate it is a sign they are in trouble. Last week the word was never far from their lips, revealing the shallowness of Sinn Fein’s grasp of basic democratic principles. Put simply, Sinn Fein seems to believe that because people vote for the party, it is above the law. It is not. Gerry Adams, its president, needs to understand that democracy requires his party to embrace the rule of law and to root out the criminality that blights the republican movement. Every time he and his colleagues opt for denial instead of responsibility, falling back on their mandate as justification for their inclusion in the democratic process, the Sinn Fein leadership erodes trust and credibility. It may play well in hardcore republican areas but it rings hollow across the rest of the land.

On Friday Sinn Fein’s credibility reached rock bottom when Hugh Orde, the chief constable of the Police Service of Northern Ireland, stated categorically that the Provisional IRA, Sinn Fein’s armed wing, was responsible for the robbery of £26.5m (€38m) from the Northern Bank before Christmas.Tony Blair and Bertie Ahern now know Adams and his colleagues have played them for fools. While the two governments were negotiating in good faith to reach a settlement in Northern Ireland, and treated the Sinn Fein leader with seriousness and courtesy, his cohorts in the Provisional IRA were planning a robbery that would inevitably derail that settlement.

Far from recognising his culpability, Adams has resorted to outraged denial. It will not wash in London or Dublin. Neither Blair nor Ahern take kindly to being made look foolish and the taoiseach can be a savage foe when he has been slighted. Both leaders must face down Sinn Fein’s blackmail. There can be no more compromises, no more pursuit of peace at any price. Sinn Fein and the IRA must abandon terrorism and criminality; on that there can be no more weasel words. If they will not, they must be excluded from negotiations about the future of Northern Ireland, which they sully with their criminal cynicism.

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