European Union chief executive Jean-Claude Juncker will propose to national leaders next month a handful of options for shoring up unity once Britain launches a withdrawal that some fear could trigger a further unraveling of the bloc.
The European Commission president wants some states to be able to deepen cooperation further and faster without the whole bloc having to follow suit, but this idea has raised concerns, especially among poorer eastern countries, that their richer neighbors may use Brexit to cut EU subsidies to them.
Juncker has said he will argue for what is commonly called a "multi-speed Europe" in a White Paper policy document.
Juncker will chair a special meeting of his commissioners on Tuesday but a spokesman said on Monday it was not yet clear when exactly the paper would be published.
Officials will not detail what the proposals are likely to be, though say they would probably not mean major institutional changes or treaty amendments for which most governments, beset by challenges from eurosceptic nationalists, have no appetite.
Some options are not mutually exclusive and could be combined, all with the aim of persuading voters disillusioned by years of economic malaise that the EU is worth preserving.
By setting out four or five practical "pathways to unity" or "alternative avenues for cooperation at 27", EU officials say Juncker aims to give the 27 leaders of the post-Brexit Union some broad choices to start considering at a summit in Rome on March 25, where they will mark 60 years of the bloc's founding.
As the 27 also try to hold to a common line in the two-year negotiating period with Britain which they expect London to launch before the Rome summit, the main aim of the Juncker proposals is to overcome internal divisions, EU officials said.
He wants to see responses by the autumn - by which time the Netherlands, France and Germany will have held elections marked by challenges from anti-EU movements that have been inspired by last year's votes for Brexit and U.S. President Donald Trump.
"This is no longer a time when we can imagine everyone doing the same thing together," Juncker said last week, echoing German Chancellor Angela Merkel and French President Francois Hollande, who called on Feb. 3 for an EU of "varying speeds."
Their remarks, however, have perplexed other states whose envoys note that existing rules already allow for "enhanced cooperation" in various fields, such as the 19-nation eurozone.
"A multi-speed Europe is a fact. No one has a problem with it," said one senior EU diplomat. "So why are they talking like this now? They are irritated with the east ... It is divisive."
Noting that a key obstacle to deeper integration of, for example, the eurozone was disagreement between Berlin and Paris on how to do it, the diplomat said talk of a two-speed approach sounded like an attempt to penalize the post-communist east.
Hungary and Poland in particular have irritated the EU by challenging its rules on democracy and resisting calls to take in asylum-seekers, while Germany has taken in over a million.
Hollande accused easterners of treating the Union "like a cash box". With Brexit leaving a hole in the EU budget, some diplomats see a push by Paris and Berlin to cut their subsidies.
German officials say Merkel does not see one specific set of countries going for deeper cooperation but imagines varying groups moving ahead in different fields. For example, defense integration is a priority for Germany.
"Some see this as a risk to unity," one senior official said of Juncker's multi-speed idea. "Others see a risk if we don't do it and we fail to aspire."