New Delhi, Oct. 9 -- French Prime Minister Sebastien Lecornu vowed the government would unveil its policy response at month-end to the growing protests for increased spending even as investors sell off French bonds.

The result is the current bond rout in France could fester for a while. France's public debt has grown to 120% of its gross domestic product, and bondholders are pressuring the government to cut spending rather than increase it.

Investors, meanwhile, are looking for signs that the fiscal mess upending the French bond market could spark further turmoil in the euro zone.

The protests leaves France in a difficult bind ahead of its spring presidential elections. They raise the prospect the French government offers "expensive co...