Germany and France have warned they will block any further EU enlargement until the Lisbon Treaty is ratified, heaping extra pressure on the Government to run a second referendum on the treaty.

The announcement by French president Nicolas Sarkozy and German chancellor Angela Merkel, who both oppose Turkey's bid to join the union, could affect Croatia, which is scheduled to join in 2010.

"For enlargement we need Lisbon. Without Lisbon we go back to Nice," said Mr Sarkozy at the EU summit in Brussels, where last week's Irish No vote to the Lisbon Treaty was the main item on the agenda.

Dr Merkel agreed with Mr Sarkozy that the EU's existing treaties would not enable the union to expand beyond its 27 members. "I agree because the Nice Treaty limited the union to a membership of 27 states and for me it is unthinkable that we would change one area of the Nice Treaty without looking at the whole of the Lisbon Treaty," she said.…