The Labour position has also, subtly but crucially, changed. Not, of course, by anything clear being said. The mantra marches on, regardless of the ridicule widely heaped upon it. The 1997 formula, that five economic tests must be passed, remains in place, unamended, on the tenuous premise that nothing has changed since that date to justify an interim judgment about whether they ever would be. Blair and Gordon Brown stuck to that yesterday.
Nobody can crack their robotic insults to the intelligence of the voters.
Offered the chance to explain why he ever said he was in favour of the euro in principle, Blair will still go no further than mumbling about currency stability. But on this occasion, that wasn't the only thing he said. While the economic tests remain the totemic challenge to be met before the campaign is formally called, it's much clearer than it was that the economy is not what the final argument will be about. Faced with this week's contributions from Lionel Jospin and Romano Prodi to the debate about the future of the EU, Blair suddenly erupted into eloquence. What will face the voters, he thereby implied, is a political question about the future role of Britain in the world.