 Chief executives of the four biggest airlines in Britain and Ireland put their business rivalry and personal animosity aside yesterday to make a united call on the Chancellor to abandon passenger taxes.  air passenger duty (aPD) is costing jobs, deterring inward investment and depriving families of their "right" to a foreign holiday, Willie Walsh, of British airways, said. "It is driving us towards a recession at a time when we need to be creating growth and creating employment," he said. "This is a failed policy of Gordon Brown that is being perpetuated by George Osborne."  Sharing a podium with Michael O'Leary, the abrasive boss of Ryanair, Mr Walsh said that there was no other issue that could unite all airline executives in the same way.  Mr O'Leary said: "Why has George Osborne not got rid of the tax? Because he lacks the courage and he lacks the balls to get rid of the tax."  along with Carolyn McCall, chief executive of easyJet, and Steve Ridgway, the Virgin atlantic boss, they have written a joint letter to the Chancellor asking him to abandon the tax and commission independent research to determine its economic cost.  The letter says: "For hard-working families, aPD is a tax too far for the privilege of taking a well-earned holiday.  It is also a tax on tourism and a tax on business."  Passenger numbers in Britain fell by 7.4 million in 2010, the third consecutive year of decline. The airlines claim that taxes are partly responsible.  aPD is due to rise by 10 per cent next april. From January, the industry will also have to buy permits for some of the carbon it produces.  The airlines said that they supported British entry into the EU Emissions Trading Scheme from January 1. "That is the environmental tax on airlines. aPD is a tax on families and consumers," Ms McCall said.  She added that the combination of the two taxes next year was "completely unjustifiable". Economic research co 