Italy hoping to gain support among founding EU members to back model, but some say it could lead to break-up of bloc

A core group of European Union founding countries is to risk the fury of Visegrád member states as it forces the resurrection of a two-speed Europe back on to the Brussels agenda six decades after the treaty of Rome.

Italy, which is hosting an EU summit next month marking the 60th anniversary of the founding pact, is increasingly confident that France and Germany will back the plan for a post-Brexit roadmap, despite bruising exchanges with central Europeans about the best way to respond to the challenge of populism.

A two-speed Europe would allow a core of countries to press ahead with closer cooperation and integration on finance, tax and security, leaving a peripheral group to continue in a looser federation.

The Italian prime minister, Paolo Gentiloni, calling for a single EU welfare system and action against austerity, said recently in London that greater integration was essential to respond to “the illusions of populism”.

But countries likely to be outside the core, such as Poland, fear that the inner group would start to take unilateral decisions with a continent-wide effect. They were aghast that the first draft of the Rome declaration made no mention of the nation state, and are wary of an EU with an integrationist group at its core.

But Italy believes it can garner enough support among founding members for the eventual declaration to back the concept. Belgium, Luxembourg and the Netherlands – who, with France, West Germany and Italy, formed the “inner six” of the original European communities – have already expressed their support.

The German chancellor, Angela Merkel, has also allied herself to the cause, saying this month: “We certainly learned from the history of the last years that there will be as well a European Union with different speeds, that not all will participate every time in all steps of integration.”

Italian officials seized on her remarks, saying they were her most public endorsement to date of the model and opened the way for a reference in the Rome document, which is still being drafted.

Sandro Gozi, Italy’s Europe minister, said: “We want to have a core shared by everyone and then there will be specific policies in which certain countries can move ahead, without other countries imposing a veto.

“In a union of 27 countries it is utopian that everyone can move forward with the same timing and objectives. A group can act as political vanguard and proceed in a more expeditious way to reach new common objectives, such as defence, economic security, combating inequalities and support to the young people.”

Gozi added that it would be easier for the EU to pursue such reforms following Britain’s decision to leave. “With the UK outside the EU it will probably be easier to move ahead with greater cooperation in this field,” said Gozi”. “It will be a win-win situation.”

The revival of the idea – long discussed in European circles – underlines the extent to which the UK will be negotiating in the coming Brexit talks with a distracted institution more interested in its own, internal reforms than a soon-to-be departed member.

But the Visegrád group – comprising Czech Republic, Hungary, Poland and Slovakia – is alarmed.

The powerful head of Poland’s ruling party, Jaroslaw Kaczyński, last week warned after meeting Merkel that any move toward a two-speed European Union would lead to the bloc falling apart, as well as the end of her political career in German elections later this year.

A two-speed Europe would lead to the “breakdown, and in fact the liquidation, of the European Union in its current sense”, he said.

The European commission president, Jean-Claude Juncker, worried that internal divisions could be exploited by the UK in the Brexit talks, is understood to be keen to minimise talk of a rift. He said on Sunday he still saw the Rome summit taking place on 25 March as largely celebratory and challenged advocates of a two-speed EU to be more precise about how it would function.