Exactly a month ago, my wife, son and I were not allowed to board a British Airways flight to Paris via London because we didn't have a transit visa, called a Direct Airside Transit Visa. This came as news to me, as well as to many people to whom we mentioned the incident later including - hold your breath - the West Europe Division of the MEA.

When we protested, the counter girl said the travel agent should have informed us that a transit visa was needed. Perhaps he should have. But what was BA's duty in the matter? When I checked the BA office in Gurgaon the next day, the girl said BA had informed all the "major" travel agents but it was not possible to inform all the smaller ones.

Really, I asked. Even when you do business with them? There was no reply to the question but she informed me that India had been added to the list of nationals who needed a transit visa around October 2004 because Indians tended to run off. I checked. Between 2001 and 2005, there have been around 1,000 such cases, as against nearly five million Indians who have passed through Britain. Talk about shabby excuses.

The girl also told me that it was up to the passenger to ensure that all travel documents were in order and that the airline had no responsibility in the matter. But that is debatable because BA encourages you to buy e-tickets, which is what we had. For paper tickets it charges $25 extra. In other words, it cuts out intermediation so that it need not pay the commission, which is usually between 3.5 and 5 per cent.

I would have thought that this exclusion imposed an additional duty on BA regarding visas, especially transit visas, because I doubt if anyone today thinks he or she can enter Britain without a visa. But transit is a different matter altogether.

Indeed, the only thing required on the e-ticket form is a field asking for visa details. If this field is not filled, the computer can be programmed not to issue a ticket. It is a simple method and effective but BA has not thought it fit to create such a field on the ticket application form.

I did not argue with the girl because it seemed pointless. Instead, I came home and checked what this transit visa thing was.

It turns out to be an extraordinary instrument of discrimination because it applies overwhelmingly to coloured people. The exceptions are Macedonia, Moldova, Serbia and Montenegro and, if you stretch it a bit, Albania (see http://www.ukvisas.gov.uk/servlet/Front?pagename=OpenMarket/Xcelerate/ShowPage&c=Page&cid=1020786334922).

It is also an instrument for earning revenue from passengers who have to transit through, say, Heathrow. This became clear when I checked the Heathrow website, which said that in 2005 the airport had handled 64 million passengers. Assuming that even a conservative 10 per cent (or about 6.4 million) of these are nationals who need a transit visa, at 30 pounds a visa it works out to a tidy 192 million pounds. The revenue - earned merely for using the toilets - goes to the UK government.

Direct Airside Transit Visa (DATV) nationals

Afghanistan, Albania, Aigeria, Angola, Bang;adesh, Belarus, Burma, Burundi, Cameroon, China, Colombia, Congo, Ecuador, Eritrea, Ethiopia, Gampia, Ghana, Guinea, Guinea-Bissau, India, Iran, Iraq, Ivory Coast, Kenya, Lebanon, Liberia, Macedonia, Malawi, Moldova, Mongolia, Nepal, Nigeria, Palestinian Authority, Pakistan, Rwanda, Senegal, serbia and Montenegro, Sierra Leone, Sudan, Somalia, Sri Lanka, Tanzania, Turkey, Turkish, Uganda, Vietnam, Zimbabwe

The amazing thing is that a transit visa is needed even if you have a valid Schengen visa. But it is not needed if you have a valid US, Canadian, Australian or New Zealand visa. And, of course, you don't need one if you are an Indian (or Chinese or Vietnamese) diplomat.

This last exemption annoyed me even more because here was another instance of those who can do something about a problem not even being aware of it. This was, it seemed to me, the exact equivalent of railway officers not being sensitive to long ticket queues, telecom officials not knowing about the cost of calls, bankers not being worried about loan hassles, and so on.

An IAS officer has no idea of what a common man has to face at the hands of the lower bureaucracy, nor a police officer of how frightened people are of his subordinates.

Anyway, since I know one or two chaps in the foreign service, and granting it was up to British citizens to challenge discriminatory laws their country imposed, I asked why India did not impose a reciprocal requirement. After all, if there is one thing the MEA is big on, it is reciprocity.

I was told that for every one UK citizen who transited through an Indian port or airport, there were at least 1,000 Indians who transited through a British port or airport. So what, I asked. Doesn't that apply to diplomats as well? There was no answer, which confirms my theory that in India those who are in a position to help, won't. This includes MPs, who, while travelling abroad, always receive VIP treatment.