THE eurozone faces a massive reduction and a more integrated format after an investigation by German and French officials.
EU sources are understood to be considering a two-speed Europe where one or more countries will leave the eurozone.
The remaining core countries will push towards deeper economic integration, including on tax and fiscal policy.
A senior EU official said changing the make-up of the eurozone has been discussed on an "intellectual" level but had not moved to operational or technical discussions.
These radical steps are opposed by many EU countries, which see as a huge change of the geo-political map and could give rise to new tensions.
"It could truly be the end of Europe as we know it," one EU diplomat said. One German official said it was a case of pruning the eurozone to make it stronger.
German chancellor Angela Merkel and French President Nicolas Sarkozy have hinted that Greece may be asked to leave the eurozone if the general stability was to be maintained.
And Ms Merkel has reiterated a call for changes to be made to the EU treaty, saying the situation was now so unpleasant that a rapid "breakthrough" was needed.
The aim is to reshape the currency bloc along the lines it was originally intended -- strong, economically integrated countries sharing a currency, before weaker nations were invited in.