France, Oct. 15 -- The 27-nation European Union wants an agreement by Christmas, worried that any future dealmaking will be derailed by potential eurosceptic wins in polls taking place across the bloc -- most crucially in key power France.

The fears are not unfounded. The frontrunner in the French vote, far-right candidate Marine Le Pen, wants to slash the country's contribution to the EU budget to help cost savings in the bloc's second-biggest economy.

Putting the screws on the EU, Le Pen said on the eve of the summit that it would be a "democratic scandal" for leaders to adopt a budget before next year's votes.

At stake is the nearly two-trillion-euro budget, which will determine the EU's main priorities for the period between 2028 a...