Stories have been emerging for some time of promiscuity in the 24-hour centres.

There was the call centre where the drains were choked with condoms, and the woman worker who told the press that she and her colleagues took condoms to work.

Hardly a cause for concern by Western standards. But in India, where attitudes to sex remain highly conservative, it has caused a minor scandal.

This is where the Catholic Church has come in, offering counselling and week-long retreats for call-centre workers "in the hope of turning staff away from a life of sin".

"We don't want to do moral policing, " the archbishop of Bangalore, Bernard Moras, said. "But we want to advise young people that being 'modern' doesn't mean losing family traditions or moral values."

The reason call centres have become the scene of sexual liaisons is simple, according to those who work in them.

It's one of the few places young men and women find themselves working together late at night. This is a country where most people still have a husband or wife chosen by their parents. But battle lines are being drawn between traditional values and a younger generation that views the world differently.

There is a sexual revolution going on in India. The young, at least those from the middle classes, date in a way their parents could never have dreamt of. In the big cities, more and more nightclubs and bars are opening up where men and women can socialise.

In Delhi this year, plastic surgeons say they have seen a 40% rise in demand, with men as well as women seeking nose jobs.

But there has been a moral backlash from conservatives, of which the Catholic Church's foray into call centres is a typical example. In Bombay and Bangalore, local governments have ordered police to start enforcing licensing hours.

Bombay's dance bars, where clients could ogle the dancing girls, have been closed down by the state government.

In part, the politicians are pandering to the vote from the millions of poor who still cannot lead the more sexually freewheeling lifestyle of the middle classes, and look on it with resentment.

A survey of call-centre workers last year found that 38% believed premarital sex was morally acceptable and a quarter regularly had casual sex. It seems that the sexual revolution has got hold of India.