According to Press Association (PA), the British news agency, Chancellor Gerhard Schröder called his Dutch counterpart on Wednesday evening to offer The Hague a chance to take part in an inner circle of EU founding members, who could forge ahead.

"Mr Schröder was on the phone the minute it was clear which way the vote was going. It clearly was not a spur-of-the-moment thing. But Mr Balkenende made it perfectly clear he wasn’t interested. He is well aware that the Netherlands would be a junior partner in such a small grouping alongside Germany and France", said a high-level EU insider, according to the agency.

The founding members of the EU are Germany, France, Italy, the Netherlands, Belgium and Luxembourg.

What will the UK do?

Aside from talk of a founding members club, the other big issue is whether countries will heed pleas by top EU officials not to unilaterally break off the ratification process.

The call has found some public support from Paris and Berlin but Britain has notably not committed itself to going ahead with its referendum.

Reacting to the Dutch referendum foreign secretary Jack Straw said "we must all respect the results of the referendums, and we do … but the verdict of these referendums now raises profound questions for all of us about the future direction of Europe".

Mr Straw is set to make a statement on the referendum on Monday (6 June).

If Britain calls its poll off, Ireland is also likely to waver while Anders Fogh Rasmussen of Denmark, another country that had committed itself to a referendum, has said he will go to London next week to discuss the situation directly with his counterpart Tony Blair.

What next?

If no country breaks the mould within the next days and stops their ratification process, EU leaders will meet in two weeks to try and form a unified response to the problem.

The leaders of the three principle EU institutions released a statement on Wednesday (1 June) saying "the Council of 16 and 17 June could usefully carry out a serious collective analysis of the situation".

The leaders are likely to look at several options. They could declare the treaty dead but this will raise questions about the ten countries, representing around 49% of the EU population, that have already ratified it.

They could decide to proceed with ratification anyway and risk a domino effect caused by the French and the Dutch No's and extremely low voter turnout as citizens wonder why they should vote on a constitution that has already been rejected by two countries.

They could also decide to freeze the ratification process while they see how the union functions under the Nice Treaty, a situation that could last several years.

Another option could be to try and save parts of the constitution they feel can be implemented without too much difficulty. However, this would most probably prompt the reaction that the will of the French and Dutch voters is being ignored.

One thing leaders will certainly be looking at is both the scale of the rejection and the reasons given for it - in the Dutch case it included feeling that Brussels has too much power and that EU integration is proceeding too quickly.