ROME (Reuters) - EU leaders will renew their marriage vows for the troubled bloc in Rome next month but may acknowledge that in future, certain member states will move closer to some partners than to others, Italy’s top European affairs official said.

FILE PHOTO: The European flag flies outside of the La Canada shopping centre in Marbella, Spain January 23, 2013. REUTERS/Jon Nazca/File Photo

The 60th anniversary of the Treaty of Rome, which paved the way for European integration, will be marked in the Italian capital on March 25 with a document expected to be signed by 27 EU leaders, committing them to a new vision for the bloc.

Originally billed as a moment of celebration, the event has been overcast by an array of existential crises for the Union, including Britain’s shock vote to leave, repeated financial trauma, migration flows and burgeoning populism.

“If the status quo carries on, then you have to doubt the future of Europe,” said European Affairs Secretary Sandro Gozi.

“We need to reaffirm that we want to be a community of 27 nations. But it is also time to recognize that we might all have different levels of political ambition,” he told Reuters.

In practice, this means that some EU countries, notably the six founding members - France, Italy, Germany, Belgium, Luxembourg and the Netherlands - are primed to push for closer integration even if some of their allies might not follow them.

German Chancellor Angela Merkel delighted those seeking a so-called multispeed Europe when she said in Malta last week that “there will be an EU with different speeds, that not everyone will take part in the same levels of integration”. [nL5N1FO65W]

Italian officials said it was her most public endorsement of the idea and opened the way for some reference to this to be included in the Rome document, which is still being drafted.

MILITARY COOPERATION

“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,” said Gozi, who is a close ally of former Italian prime minister Matteo Renzi.

In truth, Europe has already operated on several levels for many years. For example, not every country is signed up to the single euro currency or the Schengen open-border policy.

Gozi said there were many new areas that could benefit from such an approach, notably in security and defense, with some nations eager for their armed forces to work together much more closely to boost their overall efficiency.

“European spending on security is 50 percent that of the United States, but our military effectiveness is 10 percent that of the U.S.,” he said. “We definitely need to improve this.”

Britain was seen as reluctant to embrace European defense cooperation, and its imminent departure from the union will remove one impediment to EU military integration.

“With the UK outside the EU it will probably be easier to move ahead with greater cooperation in this field. It will be a win-win situation,” said Gozi.

Britain is expected to trigger formal EU divorce talks by the end of next month and the Italians have requested that this should not be done in the run-up to the March 25 event, which Prime Minister Theresa May will not attend.

“The British preferred not to come. We contacted them. They are part of the story, but they won’t be part of the future,” said Gozi.