CERNOBBIO, Italy (Reuters) – A referendum on Italy’s membership of the euro currency would be held only as a “last resort” if Rome does not win any fiscal concessions from the European Union, a senior lawmaker from the anti-establishment Five-Star Movement said on Sunday.

Seeking to reassure an audience of bankers and business leaders at the Ambrosetti conference, Luigi Di Maio, widely tipped to be 5-Star’s candidate for prime minister at a general election due by May 2018, said the referendum proposal was a “bargaining tool.”

“Austerity policies have not worked, on monetary policy we deserve the credit for triggering a debate… this is why we raised the issue of a referendum on the euro, as a bargaining tool, as a last resort and a way out in case Mediterranean countries are not listened to,” he said.

Reuters had access to the comments, which were made behind closed doors.