A British Airways employee at a rally near Heathrow on Saturday. (Reuters)

London, March 20: British Airways flights to India are being cancelled as the airline’s cabin crew began a strike over pay and conditions, their first in 13 years, at 6am to today.

Although BA management have said they intend operating the long haul flights from Heathrow, it does appear a number of services to India are “not operating”.

“Not operating means they have been cancelled,” a travel agent in London, with a substantial Indian customer base, told The Telegraph.

“You cannot get any information from British Airways,” he complained, although the airline was attempting to out some information on its website.

Pickets mounted by cabin crew, who belong to Unite, the union which has been holding bad tempered negotiations with Willie Walsh, the BA chief executive, started gathering at Heathrow at dawn.

The strike from March 20-23 will be followed by a second stoppage lasting four days from March 27. Others are expected in April if there is no resolution.

This means a nightmarish period for passengers as aircraft start to be located at the wrong airports for a proper schedule to be maintained.

The problem for passengers – and this applies to those flying to India – is that they do not always know in advance which flights are operating and which are not. To be fair to BA, the airline is making decisions minute to minute, sometimes putting back flights which had earlier been cancelled and having to cancel flights which it thought would operate.

Although the route to India is a profitable one for BA, the airline is giving priority to maintaining its transatlantic service to the United States, according to the travel agent consulted by The Telegraph.

Looking at his computer and checking what flights were available, he said: “Tomorrow, BA139 to Mumbai at 1030 is cancelled but BA199 at 1845 is showing available. To Delhi, BA143 at 1150 and BA257 at 1315 are both cancelled.”

He went on: “BA119 to Bangalore at 1350 tomorrow is also cancelled.”

Looking at availability for Monday, the agent said: “BA035 to Chennai is operating; BA119 to Bangalore at1350 is operating; and so is BA277 to Hyderabad at 1340. BA143 to Delhi in the morning is cancelled and there is no flight in the evening. BA139 to Mumbai in the morning is cancelled but BA199 in the evening is operating.”

He added: “Basically, some flights to India are operating, others are not.” It seems this will also apply to incoming flights from India.

Flights to Calcutta do not have to be cancelled because long ago, BA, in common with Air India, pulled out of Calcutta because the city was viewed economically as a Marxist backwater.

The airline is offering refunds to those passengers who do not wish to rebook for another day. However, the compensation claims for passengers who have not bought their tickets directly from the airline – and this may well be the case for hundreds in India who have got their discounted tickets via agents – may be less straightforward.

The dispute has been aggravated by the imminence of the general election since Unite is a union which makes generous donations to the Labour Party.

Tory leader David Cameron, who saw an opportunity for attacking Gordon Brown, said the strike “threatens the future of one of Britain’s greatest companies along with thousands of jobs. But will the prime minister come out in support of the people who cross a picket line and go to work to help the business? Because the Unite union is bankrolling the Labour Party and he didn't have the courage to give an answer to that question. So again, the vested interest triumphs and the people, including those cabin crew staff who don't want to go on strike, they are the ones who suffer along with all the passengers.”

The prime minister has urged the two sides to resolve the dispute.

Meanwhile, the Labour MP John McDonnell, whose Hayes and Harlington constituency includes Heathrow, attacked BA’s aggressive management style. “This dispute is a prime example of the current industrial relations climate, with the employer not only seeking to win but to break the union, too.”

Just under two-thirds of Heathrow’s long-haul services are expected to fly this weekend and less than a third of short-haul flights.

BA is planning to operate all long-haul flights to and from Gatwick plus around half of short-haul flights, while all flights to and from London City Airport are expected to fly as scheduled.

BA said it was confident of handling as many as 49,000 passengers today and the same number tomorrow, which compares with a figure of around 75,000 for a normal weekend day in March. The airline has also arranged with more than 60 other airlines to take BA customers on their flights.

The strike went ahead following the collapse of talks, which ended with Unite and BA blaming each other.

Walsh has posted a video on the BA website apologising to passengers.

“I am deeply sorry,” he said. “This is a terrible day for BA. Thousands of our staff will be serving you over the weekend. I am confident that we will be able to deliver a good service.”

Unite said early indications were that its 12,000 members were solidly supporting the three-day walkout, called in a bitter dispute over cost cutting.

On the picket lines, it was clear the battle was getting increasingly acrimonious.

Unite assistant general secretary Len McCluskey said through a hailer: “Unfortunately it has become all too clear in recent days that Mr Walsh had no intention whatsoever in arriving at a settlement. His way of dealing with business is industrial dictatorship. He behaves more like a 19th-century mill owner than a chief executive of an iconic company like British Airways in the 21st century. He has to understand, as indeed has everybody got to understand, that you cannot bully workers into accepting things they do not want to accept.”