Unions ramped up the pressure on Qantas Thursday with more than 50 flights delayed or cancelled by strike action, while border security also walked off the job over failed talks with the government. Qantas\' damaging standoff with baggage handlers and ground crew over pay and conditions, which also involves engineers and pilots, has dragged on for months with the airline estimating some 50,000 passengers have been affected so far. Transport Workers Union members at Qantas stopped work for two hours early Thursday morning at airports across the nation and were due to walk out for another two hours in the afternoon. Qantas said the action had forced it to cancel 14 domestic flights and it would delay 38 others. \"The TWU\'s claim for a 15 percent pay increase over the next three years is just not sustainable in the current economic environment, and given Qantas workers are already the best-paid in the industry,\" said airline spokeswoman Olivia Wirth. Reports said the dispute had so far cost Qantas Aus$20 million (US$20 million), but a spokesman said it was unclear what the financial impact had been. \"It\'s just too early for us to say what financial cost it\'s having on the business at this stage,\" he said. Passenger delays were compounded by separate industrial action by Customs and Border Protection staff from 7am (2000 GMT), which hit international flights. On Monday, Qantas was forced to cancel or delay nearly 80 flights when aircraft engineers threatened to walk off the job. The called off their action at the last minute but it was too late for the airline to redo its schedule. Engineers are due to strike again on Friday. Unions are locked in protracted contract talks with Qantas over the airline\'s Asia-focussed restructure, under which 1,000 jobs are to be axed. Qantas doubled its annual net profit to Aus$250 million ($254 million) in August and upped chief Alan Joyce\'s pay by 71 percent to Aus$5 million, inflaming tensions with staff, who want guarantees about wages and job security.