In a rare instance of collective defiance, many Cuban doctors working overseas are suing to break ranks with their government, demanding to be released from what they have called a form of slave labor.

Around a total of 18,000 medical professionals are part of the Mais Medicos” program in Brazil. The program is present in more than 4,000 municipalities and provides medical assistance to approximately 64 million Brazilians. The program aims to help the Brazilian health care system by supplying Cuban doctors to  Brazil’s most remote and impoverished areas. The Cuban doctors imported by Brazil are working in the program under contracts with the Cuban authorities. Brazil pays the Cuban government millions every month in exchange for their medical resources, effectively making the doctors one of Cuba’s most valuable export. However, the doctors get a very small portion of this money, and an increasing number of them in Brazil have begun to revolt.

Since last year, around 150 Cuban doctors have filed lawsuits in Brazilian courts to challenge the program’s arrangement. They demand to be treated as independent contractors and earn full salaries. The doctors demand that after the three-year cycle ends, they must be allowed to return and be replaced by other professionals.

As of now, Brazil pays Havana directly for the doctors it is supplying, leaving the Cuban government responsible for providing the doctors with a stipend. Many of these doctors are coerced to travel without families and have little guarantee that their salary will suffice for their daily needs.

Brazil has been largely successful in preventing doctors who seek to stay in Brazil, and has managed to overturn any injunctions obtained by these professionals to remain in Brazil outside the terms of the agreement which they signed for the program.

Cuba has been able to lure doctors to work abroad by keeping their wages at home and offering substantially more abroad. In 2014, Cuba raised the government salary for doctors to $64 from $25 a month. However, Brazil pays Cuba nearly four times that amount per doctor, and the government gets to pocket the rest.

Cuban doctors have revealed that they began unionizing in a Whatsapp group and eventually found an attorney who was willing to help. The legal issues are more important than ever now, because the doctors have now lost a very common backup plan: moving to the United States. The American government had established a program in 2006 to welcome Cuban doctors, in an attempt to incentivize the island’s brain drain, but President Barack Obama ended the program in January 2014 to improve relations with Cuba. This program had allowed Cuban doctors stationed in other nations to acquire permanent residency visas for the United States.

The end of the program was a huge blow to many of these doctors, as it was their way out of undesirable working conditions.  The doctors’ revolt leaves them vulnerable to the possibility of serious repercussions by the Cuban government, including being banned from visiting Cuba and seeing their families for years.