Beware of referendums. They seem so seductive but always land you in trouble

Referendums are femmes fatales, seeming to lead ministers to the Promised Land only to clobber them as they get there there.

Another British prime minister has fallen for the illusory attractions of a referendum on Europe. Indeed Tony Blair's decision to offer a plebiscite on the EU constitution is part of a depressingly familiar pattern.

Another British prime minister has fallen for the illusory attractions of a referendum on Europe. Indeed Tony Blair's decision to offer a plebiscite on the EU constitution is part of a depressingly familiar pattern.

Sensible political leaders tend to begin their careers at the top by expressing grave doubts or outright opposition to referendums relating to Europe. Gradually as their difficulties mount, the offer of a referendum seems like a blissfully convenient device or an unavoidable concession. Sooner or later the dramatic U-turn does not deliver what it promised. Instead the policy reversal lands the leader in even more trouble. Referendums are the equivalent of the femmes fatales in dark thrillers. They appear to lead prime ministers to the Promised Land, only to clobber them over the head as they attempt to get there.

For Mr Blair the Promised Land could not be clearer. The offer of a referendum deprives the Conservatives of an ace card in this summer's European elections. No longer can Michael Howard argue that Mr Blair is too arrogant to consult the voters. Instead Mr Howard will have to focus on the implications of his own opposition to the constitution. This will lead the Conservatives on to some dangerous terrain.

With the click of the prime ministerial fingers the new policy also clears the legislative path at Westminster. The House of Lords in particular will be deprived of trouble-making ammunition. In a year's time Mr Blair will be able to fight a general election campaign in which Europe is once more a separate issue, one to be resolved in a referendum at a later date. This may be enough to secure the support of Rupert Murdoch and his Eurosceptic newspapers for a third election campaign. At the same time the prospect of Mr Blair fighting a pro-European referendum campaign will reassure those who have been alienated by his timidity over Europe in the past and his passionate alliance with the United States. After the next election is safely out of the way Mr Blair could proceed to win a referendum and secure his historic objective of settling Britain's ambiguous relations with Europe. He could leave Downing Street on a high.

Except that the offer of referendums does not produce such smooth consequences. Mr Blair has given up some control of the situation and handed it over to fate, events and the unpredictable whims of the electorate. From now on nothing will go quite as planned. This is the dark lesson from the past 25 years.

In holding a referendum on Britain's continued membership of Europe in 1975, Harold Wilson had hoped to unite his warring party and settle the issue for a generation at least. In spite of winning by a big margin he achieved neither objective. By 1980 Labour was resolved to withdraw from Europe, one of the policies that provoked some senior figures to set up the SDP. Wilson had papered over the cracks for a year or two at most.

When John Major promised a referendum on the euro in 1996, peace broke out in his party for around 10 minutes. Soon the Conservatives were fighting once more over Europe, for the good reason that divisions over the substance of a policy do not go away and are often exacerbated by the promise of a vote over the issue.

Tony Blair's similar pledge to hold a referendum on the euro was more productive in the short-term. It got him through two general election campaigns by making the euro a non- issue. But there has been a less satisfactory longer-term consequence: Mr Blair has never been in a position to hold a referendum on the euro. At times he has blamed the Chancellor's sceptical obstinacy, but that has been a convenient excuse. In reality there has not been a moment when the referendum looked winnable.

The offer of a referendum can be liberating for a leader. The prospect of holding the plebiscite can reduce the same leader to political impotence.

Already there are ominous signs arising from this week's decision. Without pausing for breath, the Conservatives and the Eurosceptic newspapers are making fresh demands about the timing: Let's have it in the autumn, before any parliamentary scrutiny! They make the call as if the views of elected representatives do not matter at all. Before long they will argue that a narrow victory in favour of the constitution would not be enough. If they sense defeat they will set a much higher hurdle.

On one level they would be correct to do so. Referendums are awkwardly imprecise instruments. What constitutes a decisive victory? A marginal win for Mr Blair would not close down the arguments, whereas a defeat by a single vote would be catastrophic. In the meantime it is likely that divisions in the Labour Party, largely obscured in recent years, will resurface as the spotlight of a campaign stirs the sceptics on the centre left. It is a leap from one extreme to another. For 10 years there has been virtually no debate on Europe in the Commons and within the Labour Party. Now we are being offered a referendum on the complexities of a revised constitution.

Will the promise of a referendum make much difference to the outcome of this summer's European elections, where Labour is expected to perform poorly? I suspect not. What happens if Mr Blair wins the next general election with a much-reduced majority? Even in the golden honeymoon after the 1997 election the Government won a "yes" vote in favour of a Welsh Assembly by a tiny margin. At that time no one in the upper echelons of the most popular government for decades was confident of winning a referendum on the euro. Will the beginning of a third term be a rosier context in which to fight a plebiscite on Europe? I doubt it. As for the poor old single currency, that gets kicked further into the long grass.

There was an alternative, which was to press on as originally planned, to put the case and retain control of the parliamentary timetable. After all, this is a government with a landslide majority. The Lords would have been difficult, but not as unpredictable in their stroppiness as an electorate that has been fed poisonous propaganda about Europe for decades. With good cause Mr Blair hopes that the next election campaign will be about the economy and public services. On both policy areas he has a strong case to make. But that means the argument for Europe will be made with informed passion only once the election is out of the way. That does not leave very long to convert voters brought up on the alleged horrors of the European Union.

Mr Blair is the most pro-European prime minister since Ted Heath. He has stuck with the arduous and eccentric demands of the European Union for longer than Mr Heath, who was only in power for three and a half years. Such persistence deserves a triumphant victory. I fear the offer of another Europe-related referendum will end in tears. In Britain it always does.

s.richards@independent.co.uk