The new body of law is the product of years of fierce debate, which came to a head in a tense European Parliament vote on April 11. Protesters disrupted the vote, throwing paper aeroplanes across the chamber and chanting, "This pact kills, vote no!"

The new law requires all 27 EU member states to take some responsibility for managing asylum applications but also makes the rules stricter for applicants.

Therefore, it has been attacked by both those who want to reduce immigration and campaigners who want to make it easier for people to come to the EU.

For the latter group, the most contentious part of the package involves establishing border facilities in the EU to host asylum seekers and to screen and quickly send back applicants found to be ineligible. Applicants will spend up to 12 weeks in reception centres, waiting for a decision.

On the other hand, EU member states experiencing significant spikes in asylum applications may call for the applicants to be distributed to other EU countries.

The relocation mechanism has drawn opposition from leaders trying to reduce migration to their countries, such as Polish Prime Minister Donald Tusk and Hungarian Prime Minister Viktor Orban, who are seldom found on the same side of major EU political debates.