Nearly 40 million children in government-run schools in the state of Uttar Pradesh have been locked out of classrooms for four weeks because of an “indefinite” strike by teachers.

They are demanding a near 200 per cent pay increase because their salaries have not risen for 10 years. They had expected to be given a rise last year along with central government staff, with whom they have historically enjoyed parity. But the state wants to de-link the wages of all of its staff - not just in education - from those of the federal government.

The stand-off in the strike is set to continue as the government has rejected the demand, saying it would mean almost trebling the cost of teachers’ pay from five billion rupees (Pounds 84 million) to 14 billion rupees (Pounds 234m) , which it cannot afford.

Teachers have retorted by pointing to the huge cost of maintaining the “jumbo-size” cabinet of ministers, the largest in the country.

“If the public money can be used to keep 90 ministers in style, why can’t teachers be paid a decent salary?” asked a union spokesman.

Teachers’ basic wages range from 5,000 to 10,000 rupees a month (Pounds 83 to Pounds 163) before allowances.

Uttar Pradesh, which borders Nepal in northern India, has the lowest literacy level in the country and enrolment levels are among the poorest.

Education campaigners who have motivated parents to send their children to school fear that if the strike continues many children may drop out. They suspect that many poor parents are looking for an excuse to take their children away from school and put them to more “productive” work to supplement the family’s income.

The separation of federal and state staff wages has created industrial problems across the board. Last week the entire state was plunged into darkness as electricity staff went on strike over the same issue.