NEW DELHI: India's telecom regulator on Monday dealt a blow to Facebook's plans to offer free mobile Internet through its controversial Free Basics service, by outlawing differential pricing for data packages.

Facebook has met a backlash in India from “net neutrality” advocates, who say that because Free Basics only allows access to selected websites it violates the principle that the entire Internet should be available to everyone on equal terms.

While not ruling explicitly on net neutrality, the Telecom Regulatory Authority of India (TRAI) decided not to allow what it called “discriminatory pricing” for different data platforms or content.

The ruling suggests that Free Basics, which was aimed primarily at people in poor rural areas, will not be allowed to continue in its current form.

“TRAI has today issued the 'Prohibition of Discriminatory Tariffs for Data Services Regulations, 2016' that disallow service providers to offer or charge discriminatory tariffs for data services on the basis of content being accessed by a consumer,” Sudhir Gupta, TRAI secretary, said in a statement.

“While formulating the regulations, the authority has largely been guided by the principles of net neutrality seeking to ensure that consumers get unhindered and non-discriminatory access to the internet,” Gupta said. The policy may be reviewed every two years or sooner, TRAI said.

Critics of Free Basics, which had been suspended temporarily while the regulator's consultation was ongoing, include many of India's leading technology entrepreneurs.

India's 1.2 billion people make it a vitally important market for Facebook, which is still locked out of China, with the second biggest number of users outside of the United States.