In an indication of potentially tough negotiations ahead, France said Ireland may have to raise its ultra-low 12.5 percent corporation tax rate — a taboo in Irish politics — in return for the assistance package. French Finance Minister Christine Lagarde said Irish business taxation was abnormally low by European standards. Higher-tax countries, including Britain, Germany and France, have long seen the Irish rate as a form of unfair competition. But Irish Deputy Prime Minister Mary Coughlan told parliament the government would not be raising the corporate tax rate. “It’s non-negotiable,” she said.