Leading article: History exposes a bad law

All politicians pay homage to Nelson Mandela with the hope that some of the great statesman's gravitas, not to mention popularity, will rub off on them. But the Conservative leader, David Cameron, has managed to get more out of his meeting with the former South African leader than most.

Mr Cameron used the occasion to argue that the Tories' former leader Margaret Thatcher was wrong to brand Mandela's African National Congress as a terrorist organisation and wrong to oppose sanctions against the former racist regime in South Africa. This served two purposes for Mr Cameron. By renouncing one of the most repellent episodes of Conservative recent history, he demonstrated that his party is changing. And by pressing the flesh with Mr Mandela, Mr Cameron also indicated that he is engaged with important issues, such as poverty in Africa, in a way that former Tory leaders have not been.

But there is a broader lesson for British politics here, beyond Mr Cameron's political astuteness. This Tory ideological reversal highlights the folly of the recent legislation, pushed through by the Government, making the "glorification of terrorism" an offence. As we see, official definitions of terrorism change wildly over time. In the 1980s, the Prime Minister of the day considered Nelson Mandela a terrorist. Now her successor as Conservative leader (not to mention the present Prime Minister) regards him as "one of the greatest men alive". It is not Mr Mandela, or what he represents, that has changed in that time.

If the legislation outlawing the glorification of terrorism had existed 20 years ago, it would have made the supporters of the ANC in the UK, of which there were many thousands, potentially guilty of a crime. Perhaps the most progressive international movement of the decade could have been made illegal in Britain.

When pushing through this hastily drafted legislation, Tony Blair cited the placards waved by an extremist group earlier this year, which praised the July 7 bombings and threatened a repeat, as evidence of why we urgently need such a law. But Mr Blair ignored the fact that it is possible to prosecute such demonstrators under existing legislation governing the incitement to murder. Indeed, this is what subsequently happened.

Mr Blair seems unable to understand that sweeping and vague legislation can easily be abused by a future government more unscrupulous than his own. In fairness to the Conservatives, their party was opposed to the outlawing of the glorification of terror. There are welcome signs that they are at last learning lessons from the past. It is a pity the same cannot be said for the Government.