Cityjet and Flybe are the latest airlines to threaten to pull out of London City airport if new owners raise airport charges to cover the costly £2 billion price tag.
British Airways has already warned it will pull most of its aircraft from the East London airport if fees are increased.
The airport has been up for sale for more than six months and there is reportedly attention from five investors with the deadline for bids this Friday.
The three airlines, which make up 70 per cent of the airport’s traffic, commissioned an investigation which showed that fees are likely to be raised if London City is sold at the £2 billion asking price.
City chairman Pay Byrne said: “This brings into question the long term sustainability of airline operations at London City Airport.”
A British Airways spokesperson told City AM: “Any potential new owner for London City should be left in no doubt that British Airways can move flights elsewhere if it ramps up airport charges to fund its investment.”
London City and current owners Global Infrastructure Partners are not commenting at this stage on any issues relating to a potential sale.
Sign up to BBT’s twice-weekly newsletter