Insurers can expect some business disruption if Britain votes to leave the European Union in a June 23 national referendum, according to a QBE report.

A key concern for the insurance community is the loss of freedom to provide services throughout the EU, commonly known as passporting.

“The ability to passport and provide financial services to customers in another member state has been a crucial development for businesses,” the report says. “In the event passporting ceases, insurers and reinsurers would need to use an existing, or establish, a new legal entity within the EU to continue to provide services to their customers.”

Experts told QBE retaining the freedom to passport financial services will be a priority for the UK if it leaves, otherwise the industry will shoulder added costs and disruption to establish new legal entities.

Opinions are divided on whether London could be dethroned as the global insurance centre, with pessimists holding the view an EU exit will trigger a migration of financial services talent and companies.

“I think the future of the City of London does become questionable,” PricewaterhouseCoopers UK Partner Andy Moore says in the report. “It could well lose critical mass if we end up with another EU financial hub.”

The report, What Brexit Means for Business, is based on interviews with experts from various fields including insurance, law, accountancy, regulation and economics.

“This report does not aim to make a case for or against Brexit,” QBE European Operations CEO Richard Pryce said.

“At QBE, our planning for Brexit is at an advanced stage and our aim is to continue to support our customers without interruption.”