Intensifying the protest against European Union’s imposition of carbon tax on airlines flying into their airspace, India, China and Russia may soon respond together with a retaliatory fee on European carriers, making it difficult for them to fly east. The move, which has the potential to dent the business of EU air carriers, is expected to be announced after 27 protesting countries, including the USA, Canada, UAE, Japan, Singapore and Thailand, meet in Moscow on February 21 and 22 to chalk out retaliatory measures to the carbon tax.