British Airways and union leaders disputed the impact of a three-day cabin crew strike which began on Saturday and opponents sought to use the row to embarrass the Labour government weeks before an election, according to Reuters. The walkout over pay and jobs which began at midnight will disrupt travel for thousands of passengers after talks between the Unite union -- the Labour party's biggest single financial backer -- and management collapsed. A further four-day strike is planned later this month. BA plans to fly more than 60 percent of passengers this weekend -- some 49,000 people a day, and said all flights on a revised schedule had taken off as planned. It added that crew had reported for work as normal at London's Gatwick and City airports, with 50 percent at Heathrow. "Our operations at both Heathrow and Gatwick are continuing to go well. London City is operating as normal," it said in statement. "We aim to fly as many customers as we can this weekend in the biggest contingency operation we have ever organised." However, Unite said the strike had been backed by 80 percent of cabin crew and said BA had only been able to fly a third of its scheduled flights. The BBC said 1,100 out of 1,950 flights had been cancelled but the company declined to confirm the figure. BA said it was now intending to fly an additional 17 flights than originally planned, although Unite warned the disruption would get worse over the next few days. Prime Minister Gordon Brown has called for both sides to resolve their differences without delay, as political opponents sought to capitalise from Unite's link with his Labour party. The prospect of the first national rail strike for 16 years added to the government's problems after signal workers voted for industrial action on Friday, although peace talks were due to be held next week. Labour has strong union ties that go back to its foundation in 1900. The political director of Unite, Britain's largest union, is Brown's former spokesman. CABIN CREW The opposition Conservatives, favourites to win an election expected on May 6, said they had issued an advert on Saturday highlighting Labour's links with Unite. "Will the prime minister come out in support of those people who would cross the picket line? No, because the Unite union is bankrolling the Labour party," Conservative leader David Cameron said in a speech in London. "So the vested interests triumph and the people, including those cabin crew staff who don't want to go on strike, suffer." BA, which has 12,000 cabin crew, wants to save an annual 62.5 million pounds ($95 million) to help cope with a fall in demand, volatile fuel prices and increased competition from low-cost carriers. The airline has retrained 1,000 staff to stand in as temporary cabin crew, found passengers flights on rival airlines and chartered aircraft and crew to fulfil other routes. Last month, BA posted a surprise third-quarter operating profit of 25 million pounds, although it said it was in a worse position than last year. A spokesman said there was no estimate yet as to how much the industrial action would cost the company.