The European Union needs to "discover a soul" if it is going to be worth saving, according to a report published today.

The EU would be on stronger ground if it could develop a clearer, explicit moral purpose, the report says.

Published as Prime Minister David Cameron prepares for a 2016 referendum, those who believe in the EU need to argue for staying in from a moral and not an economic basis, says the report, The Soul of the Union, from the religion and society think tank Theos.

The report says that the EU was never envisaged as an economic project and so its future should not be decided on that basis.

Author Ben Ryan says that should people vote to leave the EU it will be a "seismic shock" for the dream of European unity and could signal the beginning of the end for the project, originally driven by a network of Catholic politicians such as the Christian Democrats, influenced by Catholic social teaching.

He says Europe at the start was "fundamentally moral" and tied up with a vision drawn from Christian, and particularly Catholic, political and social theory. He warns that this vision seems to have faded.

Rather than being a tool to an end, economics has become an end in itself.

"What was once a cohesive identity and ideology based on particular moral concerns has been hollowed out and allowed itself to be replaced by the economic consensus," he writes.

Europe as a continent remains a Christian space, and Christianity defines the culture, values, history and legal structure, he continues.

"Putting the soul back in the Union by rediscovering its sense of its own identity and moral mission will not be a swift process. It may, in fact, be simply impossible. Europe is not what it was in the 1950s, and the 28 member states may simply be too far apart ever to get back to the cohesive sense of identity and morality that the early European project once had," Ryan admits.

The issues will be debated at an event, Which Europe? on 27 January at Europe House at 6.30. Speakers include Sir Simon Hughes, Dr Helen Szamuley and Professor Brendan Simms. 

Professor John Loughlin, of Blackfriars, Oxford says in the foreword that many of the problems with the EU "derive from the failure of moral vision of today's elites."

He adds: "Furthermore, as Popes John Paul II and Benedict XVI continually reiterated, Europe should not turn its back on its Christian roots which have shaped its values and institutions. This does not mean a return to Christendom but a return to a deeper and wider understanding of what it means to be a European."