EU:Ireland will be among the last countries in the EU to ratify the Lisbon Treaty if the Government decides to postpone its planned referendum until the autumn.
An internal Government paper outlining the timetable of the ratification process (see panel below) in Europe predicts just six EU states will ratify the treaty in the autumn: Finland, Germany, Malta, the Netherlands, Spain and Sweden.
The other 20 EU states are all expected to ratify it before the summer, although legal challenges in Germany, Britain and the Czech Republic could delay this process.
The document concludes that ratification is expected to pass without a hitch in most EU member states, although it notes that there is significant press and public pressure for a referendum in Britain.
The Conservatives want the government to honour a manifesto pledge to hold a referendum on the EU constitution, which the Lisbon Treaty has replaced. However, prime minister Gordon Brown argues that the treaty is very different from the constitution, which was rejected by French and Dutch voters, and should be ratified in parliament.
On Monday, Mr Brown had a significant victory when he won a vote in the House of Commons restricting the debate on the Lisbon Treaty to just 12 days. Opposition MPs had called for 18 days, but the government motion passed by 299 to 243, a majority of 56.
Earlier, a Conservative amendment to allot 18 days to debate the Bill to ratify the treaty in the House of Commons failed by 59 votes.
Britain's ratification is now scheduled to be complete well before the summer recess, although it emerged yesterday that a major donor to the Conservatives had submitted a legal challenge to the government's decision not to hold a referendum on the treaty.
Businessman Stuart Wheeler, who set a record for single gifts to a political party when he gave £5 million (€6.72 million) to the Conservatives in 2001, said he is seeking a judicial review of Mr Brown's decision.
The treaty is also likely to face a legal challenge in Germany to determine if its provisions are in line with its own constitution. The constitutional court in the Czech Republic has also been asked to review the treaty, although most EU diplomats do not envisage that there is any serious threat of non-ratification in any state but Ireland.
A spokeswoman for the EU presidency said last night that it hoped most member states would ratify the treaty during its six-month presidency.