Newcastle Airport says an independent Scottish government could damage the region's chances of attracting new routes.
The SNP has indicated it would like to cut the level of Air Passenger Duty (APD) if it wins independence in a referendum in 2014.
Graeme Mason, the airport's Planning and Corporate Affairs Director, says if APD is cut north of the border, passengers could choose to fly from Edinburgh and Glasgow instead of Newcastle. In turn, airlines could choose Scottish airports over English ones for new routes.
More top news
"Big Sam" was spotted letting his hair down in the seaside resort weeks after securing Premier League survival for Sunderland.
A look ahead at the Bank Holiday forecast for the Tyne Tees region.
Do you want to Leave or Remain in the European Union? That's the question facing everyone in the country. But what do young people think?