France and Germany on Tuesday proposed a fresh crackdown on tax havens and offshore financial centres, insisting that banks that use them be forced to put aside higher capital to offset the risk to the financial system.

Christine Lagarde, French finance minister, and Peer Steinbrück, her German counterpart, said that they wanted leaders meeting at the G20 summit on April 2 to sign up to the idea that banks and insurers should be forced to disclose their use of tax and regulatory havens in their annual regulatory filings.