The EU has launched three months of talks on the text of a new treaty to reform the 27-member bloc.
EU leaders agreed on the treaty's outlines last month
The step, taken by EU foreign ministers in Brussels, aims to end two years of confusion after French and Dutch voters rejected a draft EU constitution.
Correspondents say there is a common desire to proceed quickly, turning the outlines of treaty agreed at a summit in June into a finished product.
The foreign ministers are also drawing up plans to send peacekeepers to Chad.
Portugal, which holds the EU presidency, submitted a first draft of 145 pages - plus 132 pages of protocols and declarations - to representatives of all member states at a short, low-key ceremony.
This marks the start of an intergovernmental conference (IGC), which is expected to thrash out a final text by a summit in Lisbon in October.
JUNE EU DEAL: MAIN ISSUES
Double majority voting delayed until 2014
Long-term EU president
High Representative for foreign affairs
Fewer national veto powers
More powers for the European Parliament
Legal experts will begin going through the text in detail on Tuesday.
Poland's Foreign Minister Anna Fotyga made clear that the deal was not done yet.
"There are several issues many countries have and we would like to clarify them. The IGC is exactly for this," she said.
She signalled that Poland was no longer insisting on renewing discussions on the length of time EU legislation could be delayed, when countries opposing it have been narrowly outvoted.
However, she said Poland wanted the rules on this delaying procedure written into the text of the new treaty itself, instead of being included in a protocol, as planned.
Ms Fotyga also said Poland reserved the right to join the UK in opting-out of the Charter of Fundamental Rights.
"They are still looking to destroy the charter, practically speaking," said British Liberal MEP Andrew Duff.
"If this infection spreads, that will mean the end of the charter."
UK shadow foreign secretary William Hague is set to reiterate the Conservative Party's call for a referendum on the new treaty in a lecture in London on Tuesday.
But Europe Minister Jim Murphy said the UK government had no plans to hold a referendum.
He said that the only other country that was considering holding one was Ireland, and that was only because of its "particular constitutional arrangements".
Looking to the world outside, EU foreign ministers instructed their military planners to prepare a peacekeeping operation to protect tens of thousands of refugees from Darfur on the Chad border.
Strongly backed by France and Britain, the mission would include at least 1,500 troops and last up to a year.