A rural movement in Nicaragua that opposes the government's plan to build a cross-country canal to rival Panama's on Wednesday said it has taken its fight to the Inter-American Commission on Human Rights.

The matter would be lodged in coming days, alleging violations of thousands of people's livelihoods and property along the route of the planned waterway, the director of the Nicaraguan Center for Human Rights, Gonzalo Carrion, told a news conference.

"All other legal avenues have been exhausted," Carrion said, explaining that Nicaragua's Supreme Court had declared invalid a lawsuit trying to force the parliament to debate the project.

The government of President Daniel Ortega awarded the $50 billion canal project to a Chinese company, HKND, in June 2013.

No excavation work has yet started, but the plan calls for thousands of people to be displaced -- 27,000 according to HKND, or 100,000 according to opponents.