SAN JUAN (Reuters) - U.S. Senate Democrats, in a letter to Majority Leader Mitch McConnell, on Wednesday called for congressional action on  Puerto Rico, demanding that legislation to resolve the island’s financial crisis include tools to restructure debt. “Restructuring legislation would not cost the federal government a single penny and would instead save U.S. taxpayers from the growing cost of inaction,” said the letter to the Senate’s Republican leader, signed by all 46 Democrats and independents. The letter is a challenge to Republicans who largely oppose letting the U.S. commonwealth restructure debt. Republican Senators Orrin Hatch of Utah, Lisa Murkowski of Alaska and Chuck Grassley of Iowa last month introduced a bill to bring Puerto Rico’s finances under federal oversight without providing for debt restructuring.  Democrats have argued that federal oversight should be conditional on allowing Puerto Rico to be governed by federal bankruptcy or debt restructuring laws. Hatch, Murkowski and Grassley are cc’d on the letter. “Puerto Rico was included in Chapter 9 of the U.S. Bankruptcy Code until 1984, when Congress inexplicably excluded it from the nationwide approach to resolving municipal insolvency,” said the letter, a draft of which was first reported by Reuters last week. The letter’s broad support is key because, with 44 Democrats and two independents on board, Democrats could block bills that do not include a restructuring mechanism. Still, that is no guarantee that Republicans, who control Congress, will draft a bill that includes one. A restructuring option would be a coup for the island’s governor, Alejandro Garcia Padilla, who has long said Puerto Rico needs to cut its $70 billion in debt to grow its economy, a stance that has faced resistance from creditors. Aside from its debt load, Puerto Rico faces widespread economic strain, including a 45 percent poverty rate and a shrinking tax base, as a growing number of citizens jump to the U.S. mainland. Senate Democratic leader Harry Reid, speaking on the Senate floor on Wednesday, said Congress must do more than hold hearings or create a task force on Puerto Rico, stressing that the island needs “to be treated as other American citizens and be able to file bankruptcy.” The letter comes weeks after House Speaker Paul Ryan demanded legislation by the end of March to address Puerto Rico.  “We urge you to match his commitment to act ... by the end of the first quarter,” said the letter to McConnell. 