By Caroline Wyatt
BBC News, Paris
For once, the French people are in the deeply satisfying position of holding their unpopular government to ransom - and keeping President Jacques Chirac on a knife-edge of suspense in the run-up to Sunday's referendum.
Chirac made a determined effort to rally the "Yes" vote
On Thursday evening, preceded by the French national anthem, and with the flags of France and Europe clearly visible behind him, the French president made an impassioned appeal to his countrymen.
First cajoling, then promising and finally threatening them with the dire consequences of a "No" vote, he exhorted the French to vote "Yes" to the European Constitution.
He also sought to defuse the threat of a protest vote against his 10 years in power.
"We must not answer the wrong question," Jacques Chirac told them.
"This vote is beyond political parties. It is not about the left or the right, and if you say 'No', you are not saying 'No' to the government.
"This is about your future, the future of your children, the future of France, and the future of Europe."
To a public sceptical about Mr Chirac's government, and even more hostile to the treaty, he promised that the Constitution was good for France.
The French still have two days in which to make up their minds
It would defend French interests even more strongly within Europe, and make the EU more powerful on the world stage, providing a counterbalance to the might of the US, China and Japan.
The French president also reassured his people that the Treaty would not allow Turkey to join the European Union without a referendum being held first.
And he promised that the French social model and its public services would remain protected - an attempt to calm French fears that the treaty would enshrine what some here see as an ultra-liberal British style economy.
But whether his arguments will sway public opinion remains to be seen.
His last two intercessions on behalf of the "Yes" campaign made little difference, and in one case actively strengthened the "No" vote, which opinion polls say now commands 55% support.
Friday is the final day of campaigning in a referendum which has utterly divided France, though not wholly along traditional party lines.
The "No" campaign has created unlikley left-right alliances
For the past two months, it has pitted the political elite against French workers and trade unionists, who are in rebellious mood - fearing that the Treaty is a charter for big business.
Justifiably or not, many French believe it will allow vicious competition for jobs and lead to even higher unemployment in France than the current 10%, with the EU's eastern European members benefiting at France's expense.
Others say that this Europe is not the one France wanted to build; it's too large, too unwieldy, and ultimately no longer best serves France's interests.
The referendum has also forged some unlikely alliances between the extremes of left and right in France, as well as the small minority of eurosceptics here.
All are united against the Treaty, though for very different reasons.
Eurosceptics such as Philippe de Villiers, Nicholas Dupont-Aignan and Jacques Myard all believe that it hands too much power to Brussels, while the far left opposes its economic slant.
On Friday, it is the turn of the opposition Socialists to try to mobilise their supporters at rallies around the country, and persuade them that this Treaty is the best France will get, and that this Sunday is no time to deliver a protest vote against Jacques Chirac - leaving them in the uncomfortable position of supporting a deeply unpopular government.
In his final appeal, Mr Chirac warned that a French "No" would bring deep instability to Europe, ultimately weakening France at home and abroad.
He made it clear that there was no better Treaty waiting in the wings if France says "No" to this one.
But the polls suggest that many French have discounted that possibility - and unless they change their minds at the last minute, are preparing to deliver a knock-out blow to the Treaty and to Jacques Chirac.