Hungary has become the second country to ratify the European Union constitution with a parliamentary vote, seven months after joining the bloc.
Hungary was one 10 countries to join the EU in 2004
The vote follows on from Lithuania, another new member, whose MPs approved the new constitution in November.
The other 23 member states must approve the document by parliamentary vote or referendum before it can take effect.
A No vote from any of the EU countries over the next two years would stop the constitution in its tracks.
Hungary's MPs ratified the text, signed by EU leaders on 20 October, by 304 votes to nine.
The first popular referendum is expected to take place in Spain in February.
There is intense scepticism in the UK, which could hold a referendum in 2006, while the outcome of similar votes in France, Denmark and the Netherlands is also uncertain.
The constitution intends to make the union function more smoothly and includes a big expansion in the number of policy areas where countries will lose their national veto. It will also create a foreign minister's post.
Hungary was one of 10 countries to join the EU on 1 May this year.
Last week, EU leaders agreed to start accession talks with Turkey next October, but the process, if successful, could take 15 years.
The EU has also announced that it will start accession talks with Croatia in April.
Bulgaria and Romania are hoping to join the bloc in January 2007.