EU leaders, wary of public doubts and 'green' concerns, to sign bloc's new treaty

European Union leaders gathered in Lisbon on Thursday to sign a new treaty they say is a milestone in the bloc's history.

The signing was taking place, however, amid complaints that the heads of government were not planning to hold referendums on the document, and accusations about environmental damage they were causing by flying to a two-hour ceremony.

The Lisbon Treaty, endorsed by the EU's 27 leaders two months ago after years of unease among Europeans about how much sovereignty they should surrender to a centralized administration, replaces a thwarted project to establish a European Constitution.

The treaty scraps the system under which the …