Over 100 Indian workers, who allegedly faced 'slave-like treatment' in a Mississippi shipyard and unhelpful attitude from the embassy here, have threatened to stage a satyagraha in Washington if New Delhi does not take up their cause with the US government.

The protesters, who launched a 'long march' from New Orleans to Washington -- a distance of 1,500 km, on Tuesday, alleged that the Indian government failed to protect them.

They are expected to reach Washington DC on March 26 to meet Indian Ambassador Ronen Sen in their search for justice.

"We write in response to your seven-day-long silence, followed by a 97-word letter that adds insult to the workers' injury as survivors of human trafficking. Apparently 18 months of human trafficking merited less than 100 words from you," the workers have said in a letter to Sen. "You leave us no choice but to launch a satyagraha so that the truth will come to light and justice will be served."

"My doors are always open to any of my fellow citizens of India," Sen had said in a letter to Saket Soni of the Alliance of Guest Workers for Dignity.

"I am willing to receive you and other Indian workers at my office at a mutually convenient date and time to see how legitimate grievances and concerns could be met," Sen had said in the March 17 letter, adding that a report submitted by Indian officials on the matter is being examined.

The Indian workers have made a number of demands, including asking the Ambassador to pressurise the US State Department to restrict travel to India for their employer Signal International's US recruiters.

They also want India to put pressure on the US government to halt any expansion of the guest worker programme until both governments have adopted an agreement that reflects the interests of workers, as well as companies and recruiters.

"These workers received a harsh education in the caste system of the United States," said Soni, also director of the New Orleans Workers' Centre for Racial Justice.

"The Indian government must look these workers in their face and decide: On what terms is India willing to send its citizens to become indentured servants in the United States?" he said in a statement.

The workers quit their job in a Mississippi shipyard and sued the employer demanding 'tens of millions of dollars' in damages for allegedly bringing them to the US on a false promise of permanent residency and forcing them to work under inhuman conditions.