IndiGo, Air India and SpiceJet have opposed the government’s directive barring airlines from charging for the selection of at least 60 per cent of seats, cautioning that the move may push up airfares.The Federation of Indian Airlines (FIA), representing the carriers, has called on the civil aviation ministry to reconsider the decision. In a letter to civil aviation secretary Samir Kumar Sinha on Thursday, the body said the directive could have unintended and adverse implications for the aviation sector.“The financial impact of the directive on airlines will be significant, compelling airlines to recover the lost revenues through increases in fares. As a result, all passengers,…