French President Francois Hollande has demanded the US stop any eavesdropping on EU diplomats and suggested that the surveillance scandal could derail free-trade negotiations worth billions.

President Francois Hollande’s Socialist Party, bolstered by left-wing allies, is poised to take control of France’s lower house of parliament so he can revamp a country his partisans see as too capitalist and push to save the eurozone through growth.