PRAGUE (Reuters) - A British vote to leave the European Union would give a boost to separatist and nationalistic forces across the bloc, Czech Prime Minister Bohuslav Sobotka said on Friday.

Czech Republic's Prime Minister Bohuslav Sobotka speaks during a ceremony to sign bilateral agreements with Israeli Prime Minister Benjamin Netanyahu (not seen) in Jerusalem May 22, 2016. REUTERS/Ronen Zvulun

Sobotka also told the Reuters Eastern European Investment Summit that any easing of EU sanctions on Russia, introduced over Moscow’s role in the conflict in Ukraine, must be tied to implementation of a peace agreement.

Joining a chorus of European leaders including German Chancellor Angela Merkel and European Central Bank chief Mario Draghi, the Czech prime minister said the EU had done what it could to accommodate Britain’s wishes for special arrangements.

A vote to exit “would be a signal for separatists and also a certain signal for radical nationalists who have a program of breaking up the EU,” Sobotka said.

Opinion polls suggest Britons are almost equally split on whether to vote to leave the EU on June 23.

“I wish for Britain staying in the union and I think we as Europe have done the maximum for it by being able to agree and accept some demands of Great Britain,” Sobotka said.

European and British leaders agreed in February on measures giving Britain a special status in the bloc, aiming to avoid the uncertain repercussions of a vote to leave.

Sobotka said a Brexit vote could encourage breakaway groups in places such as Catalonia, which has long sought independence from Spain.

But he did not see a British exit adding to already widespread grumbling about the EU in central Europe, where some governments resisted pressure from Brussels to take in people fleeing war and poverty in the Middle East and Africa.

“I don’t think there will be another wave in central Europe, here refugees have played a role and handed populists and nationalists a relatively hefty amount of ammunition,” he said.

RUSSIA SANCTIONS TIED TO MINSK AGREEMENT

The EU must also decide whether to extend sanctions against Russia, adopted after the annexation of Crimea, which expire in July.

Sobotka said sanctions should only be lifted hand-in-hand with progress in meeting the Minsk peace agreement, a similar stance to that taken by Poland’s Deputy Foreign Minister Konrad Szymanski at the Reuters summit.

“Apart from a swap of prisoners, which is positive and encouraging, I do not see any other significant progress,” Sobotka said.

“That can of course change in several months and I would be glad if it changed. However Europe should respect some principles, and if we connected the economic sanctions with the Minsk agreements, we should keep that connection.”

The EU is trying to preserve unity on sanctions, which have been questioned by Hungary, Greece and Italy. An adviser to German Chancellor Angela Merkel said on Thursday it was “far to early” to discuss an easing of the sanctions.

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