By Nektaria Stamouli 

ROME -- Pope Francis told European Union leaders to work together and withstand the temptation of "centrifugal forces," just after last-minute demands by Greece risked spoiling the bloc's 60th anniversary.

In an unprecedented move, the pope received the leaders of all EU countries except the U.K. on the eve of celebrations marking 60 years since the signature of the bloc's founding treaty. Apart from papal funerals, there has never been such a large number of European leaders at the Vatican at the same time. The leaders were accompanied by their spouses, including Luxembourg Prime Minister Xavier Bettel's same-sex partner.

The pope said that at 60, the European Union "is called today to examine itself, to care for the ailments that inevitably come with age, and to find new ways to steer its course."

He spoke of "centrifugal impulses" and populism threatening the bloc, as well as a "growing split" between citizens and European institutions, "which are often perceived as distant and inattentive."

But unlike his speech to the European Parliament in 2014, when he compared the EU to a "grandmother" that was "no longer fertile and vibrant," the pope said that the EU can regain "new youthfulness" if leaders work together again.

The papal advice came just hours after the European Commission, the bloc's executive, defused a fight with Greek Prime Minister Alexis Tsipras, who threatened spoil the Saturday celebrations if the EU didn't back Greece in its latest dispute with international creditors. The pope appeared to take more time to speak to Mr. Tsipras than to other leaders during the ceremonial one-by-one greeting.

European Commission President Jean-Claude Juncker said during a meeting with trade union leaders in Rome that some of the social rights acquired in Greece shouldn't be changed at the request of the International Monetary Fund.

"We should not try to change Greek legislation when it comes to strikes, " he said.

In a letter to Mr. Juncker and other top EU officials, Mr. Tsipras backed down from earlier threats not to sign the Rome Declaration -- a document aimed at projecting unity among the bloc's 27 members in the face of U.K.'s departure -- unless there is a statement from the EU that the bloc's rules on social rights will also be safeguarded in Greece.

Greece's bailout has hit has an impasse over the IMF's demands that Greece further deregulate its labor market, which Mr. Tsipras's ruling left-wing Syriza party says goes against European norms on worker protections.

"I ask for your support in order to protect, together, the right of Greece to return to the standards of the European social model," Mr. Tsipras said.

Germany's government said Wednesday that it rejected any attempt to link the Rome declaration with Greece's bailout talks.

Greece's eurozone creditors, led by Germany, want the IMF to return to participating as a lender in Greece's bailout program after a three-year hiatus. The IMF first wants Greece to sign up to tough economic overhauls, including business-friendly deregulation of the labor market.

Syriza, however, is seeking to restore the wage-bargaining powers of Greek labor unions, which were relinquished as part of Greece's repeated bailouts since 2010. The ideological clash over labor rules is threatening to undermine progress toward economic recovery in Greece.

Mr. Tsipras's office released his letter late on Thursday as the latest negotiations between Greek finance officials and creditors were winding up in Brussels. Greek and creditor officials said there was progress but no agreement.

In a speech at the University of Rome earlier on Thursday, the Greek leader attacked the EU for letting the IMF put pressure on Greece for free-market policies that, he argued, went against European values.

"The fact that EU does not defend its own achievements, its own legacy, its own social model, the fact that EU has surrendered to the IMF explains why Europe is facing an existential crisis today," Mr. Tsipras said.

--Francis X. Rocca in Rome contributed to this article.

Write to Nektaria Stamouli at nektaria.stamouli@wsj.com

(END) Dow Jones Newswires

March 24, 2017 14:19 ET (18:19 GMT)

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