The likely consequences of rejection:The Lisbon Treaty could not be implemented and the current decision-making structures agreed under the Nice treaty in 2001 would continue to apply.
• Some minor reforms not requiring treaty base might be introduced.
• The Government could order a rerun of the referendum, although observers warn that it would not be easy to come up with Nice-like Irish protocols to sweeten the pill.
• EU likely to face a similar crisis of confidence to the one that it suffered when the French and Dutch rejected the EU constitution in 2005.
• Taoiseach Brian Cowen and the Government would lose credibility at EU level, possibly undermining Ireland's influence in upcoming talks on a range of issues.
• EU leaders unlikely to agree to try and draft a new EU treaty in the short to medium term.
• It is possible that some EU states would attempt to move ahead with closer integration on their own - a situation Irish diplomats fear would isolate Ireland at EU level.