Successful political leaders only start fights they know they can win, so when Tony Blair does decide to put joining the single currency to the vote, it's a fair bet Britain will end up in the euro.
He has delayed starting that fight only because at the moment he feels he would not win, so the political cost of the battle would be too costly to contemplate.
The stakes became clear when after the last election there was intense speculation about when he would judge the time was right for a vote.
The response of Mr Blair and Chancellor Gordon Brown was to agree to rule it out in this Parliament, saying there was no way Britain would be one of the countries joining the single currency in the first wave, because its economy was not converging with the other proposed members fast enough.
The decision was officially made for sound economic reasons, but it also achieved the political objective of putting off the explosive and devisive issue until after the next election.
The Government's position now is that it believes membership of the single currency in principle could benefit Britain, but it will not join unless it is clear that it will be in the country's interest to do so.
The unwritten part of the policy is that Labour will not consider putting the matter to the test until it is confident the British people will support such a change and will vote "yes" in a referendum.
Ultimately Labour's high command intends to take Britain in and wants a "yes" vote, otherwise they would not have bothered granting semi-independence to the Bank of England: that decision was all about preparing Britain's economy to join the single curr ency.
On their side are grouped most of their MPs, a few big name Tories who have survived the Major and Thatcher years, the Liberal Democrats, most of the big business community led by the CBI, and the vast resources of the European Commission.
Together they are already working on getting the British people to vote their way in a referendum.
Small businesses are being urged to prepare for the euro and the political language used in debates gets slowly more pro-single currency.
The pro-euro language used by Mr Blair became so obvious it provoked the infamous Sun front page, in which he was branded "the most dangerous man in Britain" because he wanted to abolish the pound.
The paper's shot across Mr Blair's bows was a reminder of the forces that will line up against him when the campaign for a referendum gets under way.
He will be opposed by The Sun and other papers owned by Rupert Murdoch, as well as The Daily Telegraph, and the Daily Mail. The ever-more Euro-sceptic Tory party will fight him every inch of the way and the Institute of Directors will be a lone business voice opposing the euro.
It will therefore be a fairly even division of resources between the two sides, even though some anti-euro groups feel masses of tax-payers' money are about to be spent on propaganda by the Government and the European Commission.
Official pro-euro propaganda may indeed make an appearance, if it has not already, but its influence will be more than balanced by the Euro-sceptic titles that dominate Britain's newspapers.
How will the voters react to the conflicting messages ?…