By Sanjoy Majumder BBC News, Delhi

College students have in the past protested against quotas

India's Supreme Court has upheld a move by the government to allocate quotas for promotions in government jobs for lower caste Indians.

But the court said that the authorities would have to prove that these groups were poorly represented in government.

Such affirmative action plans for lower castes are a hugely controversial issue in India, resulting in big protests.

A government job in India is highly coveted, with many seeing it as a ticket to economic security.

Poorly represented

It is also valued for its power and prestige.

That is one reason why moves by the government to set aside quotas for promotions in those jobs has divided Indians down the middle, with some people challenging the move in court.

Now the country's highest court says the move is justified as long as the government is able to prove that the lower caste groups who stand to benefit are poorly represented in the bureaucracy.

The court also said that all affirmative action quotas should be capped at 50%, and that prosperous lower caste members should be excluded from the plan.

While job quotas have existed in India for years, most top positions in the civil service are still held by upper caste Indians.

But those opposing the move say it is aimed at winning the votes of the politically influential lower castes and will do little actually to remove inequities.

India is already in the midst of a controversy over a move to increase quotas for lower castes in elite professional colleges.