A general strike in India in May cost the economy an estimated $320m

Trade unions have expressed shock at the ruling and vowed to fight it.

Judge MB Shah said: "Government employees have no fundamental, legal, moral or equitable right to go on strike."

The ruling relates to cases arising from a major strike in India's southern state of Tamil Nadu last month as a result of which the state government sacked 176,000 employees.

Most of the employees were reinstated after a Supreme Court intervention but only after providing a written apology and pledging not to take part in strikes in the future.

Correspondents say Wednesday's ruling is likely to cause controversy in India, where trade unions command the support of millions of members.

Collective bargaining

Wednesday's Supreme Court ruling said that "no political party or organisation can claim a right to paralyse the economic and industrial activities of a state or the nation or inconvenience the citizens."

It is a dangerous and cruel attack on our right to strike Swadesh Debroy, Centre for Indian Trade Unions Analysis: India's strike ban

But, Judge MG Shah conceded that trade unions did have the right to conduct "collective bargaining" on behalf of employees.

The National Secretary of the Centre for Indian Trade Unions, Swadesh Debroy, described the ruling as "a dangerous and cruel attack on our right to strike."

"We are surprised and shocked and anguished about the honourable court's decision."

He vowed that trade unions would oppose the ruling "tooth and nail".

Paralysis

Strikes cost government and industry millions of dollars each year.

A truck strike in April crippled India's delivery network

Trade unions and political activists in India regularly impose shutdowns across whole cities.

In July more than a million state government employees and teachers went on indefinite strike in Tamil Nadu to protest at a cut in their pensions.

Nearly 6,000 of the employees suspended by the government remain out of work and face police action.