Ministers are considering holding the referendum on the EU constitution on the same day as next year's local government elections.

The idea, which is contrary to Electoral Commission advice, is being condemned by the Conservatives and 'no' campaigners, who say it will confuse voters.

According to the European Union Bill, published yesterday by Jack Straw, the referendum will ask: "Should the United Kingdom approve the treaty establishing a constitution for the European Union?"

In an accompanying article, the foreign secretary argued it was time for pro-Europeans to "reclaim the flag".