Cathay Pacific passengers could be put on flights run by mainland airlines again in coming weeks, as pilots prepare to vote tomorrow on stepping up industrial action. The news came as Cathay said it had carried 22 per cent fewer passengers last month than in July last year, partly due to the pilots' work-to-rule. The airline confirmed last night that it had already used one chartered plane on a Vancouver to New York flight yesterday because of a crew shortage. Arrangements have been made with airlines in Asia and around the world for other jets to be used if the situation worsens. 'We have some contingency plans in place which include leasing aircraft from mainland carriers if they're needed,' corporate development director Tony Tyler said. Cathay leased 17 planes from other airlines, including mainland carriers, during the first wave of the industrial action, which began last month after negotiations on pilots' pay, rosters and working conditions collapsed. The airline resumed operating with all its own planes on August 2 and since then has been telling passengers flights are back to normal and that the dispute is 'effectively over'. The Vancouver flight was the first run by a chartered airline since then. Canadian carrier Sky Services International flew the Vancouver to New York sector. Union members are due to meet tomorrow to vote on an official escalation of their campaign.