Borrowing costs for France's sovereign debt rose 11 basis points on Thursday during a surge in market volatility. The yield on 10 year government bonds climbed to 4.56%, a peak not seen since 2008. The spread between French and German 10 year securities expanded to 100 basis points, the first time that gap has occurred since 2012.

Prime Minister Lecornu told Le Figaro on September 17 that rising interest rates will add €10 billion to debt servicing costs. He projected a 2027 budget deficit exceeding 6.5% of GDP without corrective measures, which would require a budgetary effort of approximately €54 billion. These fiscal targets are intended to stabilize the nation's borrowing costs.