YESTERDAY'S hint from No 10 Downing Street that Tony Blair might be willing to concede the need for a referendum on the European Constitution was unexpected, to say the least. Despite persistent pressure from the Opposition, the media and many influential organisations the Prime Minister has until now ruled out a referendum as unnecessary unless the outcome of the current negotiations were to cut across Britain's position on such red line issues as taxation, social security, defence and foreign policy; he has also consistently said that he does not believe he will lose the argument on these sensitive areas.
So how should yesterday's guidance from No 10 be taken? Does it mean that Mr Blair, in his new listening mode, thinks that a referendum should be held, regardless of how successful he is in the negotiations? Unlikely. More probably it is intended as a negotiating tactic to send a warning to other EU countries not to make life difficult for Britain over its no-go areas since a UK referendum could easily result in a No vote - a serious matter because the Constitution cannot come into legal force unless it is ratified (either by referendum or parliamentary vote) by all 25 member states. In other words, a failure by the British people to vote for the Constitution would in effect be a veto on the whole project. Such an outcome would create a crisis in the enlarged EU for which Britain would not be forgiven.
By giving an advance warning of these dangers the Prime Minister may be trying to tell those countries wanting to push Britain beyond its red lines on taxation, social security, defence and foreign policy that the outcome could be disastrous for the EU as a whole.