Western members wanting closer integration are moving ahead with plans for deeper integration with the EU’s founding members, while leaving resistant eastern nations at their current levels.
But countries grouped in the slower tier, one of them likely to be Poland, fear they will get left behind as the more prosperous countries steam ahead.
Speaking at an economic conference yesterday he said: “A division of the Union into a multi-speed union will not be beneficial … politically, will not be beneficial economically.
“In my opinion it will ultimately lead to a break-up of the European Union.”
Tensions are already high between the European Union and its eastern members, with Brussels interfering with the Polish government’s quest for greater control in its legal system.
And the European Commission is taking legal action against Hungary and Slovakia for refusing to accept its quota of migrants.
As well as a two-tier, multi-speed union, a divide between northern and southern Europe also rings arms bells with Greece, Italy and Spain, who fear a similarly negative outcome.
Mr Duda, an ally of Poland’s ruling eurosceptic Law and Justice (PiS) party, said: “If EU membership becomes less attractive for countries that are thrown out of the first decision-making circle, then this moment in my opinion will be the actual beginning of the end of the union.
“Sooner or later the societies of states that today view the EU positively … will feel rejected and support for the EU will decline, which will result in further Brexits.”
Since PiS won an election in 2015, it has clashed with Brussels over a range of issues, including the migrant quotas.
Vociferous supporter of the EU, Mr Macron, recently criticised Warsaw, saying it was moving in a direction at odds with the EU’s core values.
He said Poland would not be able to dictate Europe’s future, but his comments were met with anger.
Mr Duda said French leader – the youngest since Napoleon – was inexperienced and arrogant.