French President Nicolas Sarkozy will walk out of this week’s Group of 20 summit if his push for stricter international financial regulation flops, Finance Minister Christine Lagarde told the British Broadcasting Corp.

Sarkozy will refuse to sign any statement if he feels “the deliverables are not there,” Lagarde said in the interview. “I think he is very determined.”

"It’s a bombshell to be honest,” said Philip Whyte, senior research fellow at the London-based Center for European Reform. “If such a high-profile leader would walk out of the summit, it likely would be seen as very negative on the stock and bond markets. It would highlight the disunity among the leaders when the times require a show of unity, concrete actions and stabilization.”