Cameron steps up EU reform push
The Prime Minister is to stress the importance of cutting red tape to tackle the youth unemployment crisis gripping much of the continent.
European Council president Herman Van Rompuy has made improving the job prospects of young people the main theme of the two-day gathering.
Some 5.6 million are out of work in the eurozone, and in Greece and Spain the unemployment rate has rocketed to over 50%.
Mr Van Rompuy is emphasising the need for money to be pumped into projects that could boost their employment chances.
But Mr Cameron is expected to argue that loosening labour market rules and freeing up small and medium companies to take on young staff is more important.
The premier has staked Britain's continuing membership of the EU on his ability to negotiate fundamental reform of it - with an in-out referendum due to be held in 2017 if the Tories win the general election.
The leaders are hoping to finalise details of the seven-year EU budget deal they agreed in February, but which has been encountering resistance from the European Parliament.
Mr Cameron could also face questions from German Chancellor Angela Merkel and others after it emerged that eavesdropping agency GCHQ has been mass-monitoring global phone and internet traffic.
Berlin has openly challenged the validity of the Project Tempora surveillance operation, the existence of which was revealed by US National Security Agency whistle-blower Edward Snowden.