France Says No...

"Then begins the Battle for Britain...but first the first skirmish will be to ensure that the slippery PM is not allowed to wriggle away from his obligation."

The U.K government must honour their manifesto commitment to the people to carry out a referendum to ratify the E.U. constitution.
The government do not have the power to cancel the E.U. Constitution. However, events in Brussels may bring about, through the European Council meeting on 12th June, an attempt to prevent any further ratification in countries still to do so, including U.K. Mr Blair will of course be attending any such meeting.

The Question

Will Mr Blair, on behalf of the people of the U.K., insist on our referendum going ahead at any such meeting. He must be made aware by people, press and media that cancellation of the referendum is not an option.

It is usually the case that the issue put is agreed by concensus unless one or more member state objects. If there were a formal vote it would be agreed by a majority, but it is unlikely that they will wish to be seen to be divided.
The Council has no power or formal authority.
However, it is usually the case that the first communiqué is that they are all agreed…then we will only have the accounts from the politicians themselves.

So, Mr. Blair, we expect you to demand that the British people be allowed their referendum regardless of the vote in France and regardless of the result in Holland.If you do not then the wrath of the British people will be too great for you to hide from.