The four biggest political groups in the parliament will be the European People's Party, the Socialists, a new Liberal and centrist group and the Greens.

ECONOMIST: European elections

There are groups, like the Socialists in the European Parliament, who are warning against the budget becoming a victim of domestic political infighting.

BBC: Britain's fight over EU budget as Brussels seeks rise

Organised by conservation groups IUCN and Birdlife, the high-level debate at the European Parliament in Brussels will consider measures that could be taken within the EU policy framework to mitigate the present and future threats from invasive alien species.

BBC: Report tracks threats from Europe's alien invasion