Germany and France are exploring radical methods of securing deeper and more rapid fiscal integration among euro zone countries, aware that getting broad backing for the necessary treaty changes may not be possible, EU officials say.

Germany's original plan was to try to secure agreement among all 27 EU countries for a limited change to the Lisbon Treaty by the end of 2012, making it possible to impose much tighter budget controls over the 17 euro zone countries -- a way of shoring up the region's defenses against the debt crisis.

But in meetings with EU leaders in recent weeks, it has become clear to both German Chancellor Angela Merkel and French President Nicolas Sarkozy that it may not be possible to get all 27 countries on board, EU sources say.

Even if that were possible, it could take a year or more to finally secure the changes while market attacks on Italy, Spain and now France suggest bold measures are needed within weeks.

As a result, senior French and German civil servants have been exploring other ways of achieving the goal, either via an agreement among just the euro zone countries, or a separate agreement outside the EU treaty that could involve a core of around 8-10 euro zone countries, officials say.

No firm decisions have yet been reached.