The European Parliament's transport committee is due to vote on whether to back proposals for a single unified launch date of 2012 for both international and intra-European flights in the European Union's emissions trading regime.
The move to include international flights in the scheme remains highly controversial although the EC proposed exempting them until 2012, unlike intra-EU flights which would launch the scheme a year earlier in 2011.
Support within the committee for a two stage roll-out appears to be faltering.
Transport committee rapporteur Dr Georg Jarzembowski says one single launch date in 2012 "would give third countries an opportunity to join or build up equivalent systems".
He adds: "this would a give a fair opportunity to airlines within the newly acceded EU member states who were only able to start developing their infrastructure in relatively recent years."
Source: Flight International