Interior ministers decided on 5 December 2006 to go ahead with the enlargement of the Schengen area to include the ten new member states that joined the Union in 2004. Land and sea borders will be phased out from 31 December 2007, and airports will follow from 29 March 2008 at the latest.
Portugal presented a compromise proposal that put an end to the tensions between the old and new member states. The deal foresees that the EU-10 temporarily maintain their old visa-data system, SISone4all, until SIS II is in place.
Finnish Interior Minister Kari Rajamäki said: "The abolition of internal border controls will have a great impact on the security of our citizens. For this reason, we must make sure that the Schengen Information System is secure and that the new member states are ready to fulfil all the requirements of the Schengen acquis."
The Schengen enlargement is tied to two conditions: the new member states must fulfil the security requirements for their external borders and the Schengen information system must be functioning in the new member states. This means that the new member states may join the Schengen zone at different times, according to their preparedness.
The cost of the enlargement of the network will be borne by Schengen members only.



