Most of the EU's leaders met on Sunday to tackle the complex dispute over undocumented migrants.
The hastily arranged informal talks in Brussels come ahead of a 28-29 June EU summit, expected to focus on this dispute as well as the difficulties raised by Brexit.
What are the divisions?
The buzzwords in Brussels are "responsibility" and "solidarity", and the balance between the two.
How much should front-line countries such as Italy and Greece be expected to do when migrants arrive at their borders? How much of the burden should be taken up by their EU neighbours?
The member states and European institutions have spent more than two years trying to agree reforms to help them cope better than during the 2015 migrant crisis.
EU leaders wanted to reach agreement by the end of June.
The debate has been super-charged by:
- the formation of a new Italian government which is Eurosceptic and talks and acts tougher on immigration than its predecessor
- Italy's decision to prevent the Aquarius - a boat carrying migrants and operated by a charity - from docking in an Italian port
- tensions within Germany's coalition government.
The European establishment fears that the issue threatens the long-term future of one of its most cherished achievements - the Schengen passport-free area.
And that a free-for-all of approaches by individual member states threatens EU cohesion.
What's on the table?
The discussion centres on the EU rule - "the Dublin Regulation" - that says refugees should be considered for asylum in the first safe country where they arrive.
What level of checks should be done to work out if someone is a refugee, entitled to asylum because they are at risk of persecution back at home, or if they are an economic migrant, who is not?
How should governments deal with asylum seekers and migrants who go from country to country - known as "secondary movements"?
Should there be a quota system for sharing out arrivals? A temporary scheme introduced in 2015 is widely seen as a failure.
The European Commission has proposed a permanent mechanism, where countries facing a big influx would get help and countries that did not want to accept people from elsewhere could make financial contributions instead.
What role is there for charities to help with search and rescue operations in light of the row over the Aquarius?
What has been agreed?
There is an EU Coastguard and there will be an EU Agency for Asylum.
The EU's fingerprint database - Eurodac - is being beefed up. EU-wide rules, procedures and conditions for asylum seekers are on the horizon.
Why have a meeting?
German Chancellor Angela Merkel requested the pre-summit gathering. European Council President Donald Tusk would prefer this issue was dealt with by all 28 heads of government together, so hosting duties have fallen to European Commission President Jean-Claude Juncker instead.
At least 17 countries are attending. Poland, the Czech Republic, Slovakia and Hungary - who form the "Visegrad Four" group - have said they will not take part. They refuse to take in any asylum seekers from holding centres in other EU states.
Some countries' prime ministers will be there; others might send ministers.
To maintain the EU's administrative integrity, it is being called an "informal working meeting" - not a summit, or a mini-summit.
What will emerge?
It is not clear what the outcome will be. A Commission-authored draft statement was circulated on Wednesday. It was interpreted as dealing with German concerns more than Italian ones.
Italian Prime Minister Giuseppe Conte used his Facebook page to say the document was unacceptable and should be withdrawn. He suggested the only output from the meeting would be a list of subjects that were discussed.
Will there be reception centres outside the EU?
This idea has been gaining traction.
The leaders of Denmark and Austria have spoken about establishing migration facilities in European countries outside the EU.
All EU leaders will discuss the idea of "regional disembarkation platforms" at their summit, according to a leaked document.
But there are lots of questions about what that phrase means: EU-agreed ports of entry for boats carrying migrants? Offshore centres? New deals with non-European countries? And would such centres conform to EU laws and values?