Europe could not be all things to all people, Prime Minister Joseph Muscat told EU leaders at an informal summit gathered in Slovakia today. 

Disagreements over taxation, immigration and the EU's relations with Russia and Turkey were bound to happen, he said. 

"This is nothing new, such tensions have existed in the past too. The difference is that the European family is bigger and less homogenous these days," the Prime Minister said. 

He insisted the EU's four key pillars - the free movement of goods, services, capital and labour - had to remain at the core of the European mission, although abuse by welfare shoppers who crossed borders to maximise their social benefit income had to be curbed. 

Dr Muscat also said that Europe seemed to adopting a protectionist tone, at a time when the forces of globalisation were more powerful than ever before. 

"We need an unprecedented push to maximise the potential of the single market, which means more and better jobs," he said, arguing that this had to happen in tandem with social policies aimed at better managing globalisation's social impacts. 

Leaders of 27 EU member states have convened in Bratislava to have what European Council president Donald Tusk has called a "brutally honest" conversation about the EU's future. 

German chancellor Angela Merkel admitted the UK's Brexit vote had plunged the EU into a "critical" situation, and said leaders had agreed to use the next six months to develop a plan to reinvigorate the Union.