Up to 700 pilots at the airline Flybe could take industrial action if a challenge over pay and working patterns is not addressed, a union has said.
The British Airline Pilots' Association said a pay claim submitted to Exeter-based Flybe this year had been ignored.
It said it also had concerns over how flying schedules were being organised.
The airline said it was in structured negotiations with the unions about a range of issues. It added that further discussions were being scheduled.
The British Airline Pilots' Association [Balpa] said the pay claim was submitted in February and that the request, which also includes pension arrangements, must be settled in the "coming weeks".
It has accused Flybe, which is 15% owned by British Airways, of putting all its resources into its proposed stock market flotation next week. The airline plans to issue £60m in new shares.
Reg Allen, Balpa's head of industrial relations, said: "Unless the company sorts out these problems quickly, it could lead to industrial action."
The airline said: "Flybe is fully engaged in this process with Balpa, while also progressing its planned IPO [initial public offering on the stock market].
"As the IPO will lead to the one third of our employees realising value in the company, and will lead to all employees having the chance to become shareholders, we are surprised that Reg Allen has chosen to raise issues in this way."
The airline started out in 1979 as Jersey European Airways, renaming itself Flybe in 2002.
It acquired British Airways' UK internal flights subsidiary, BA Connect, in 2007, and is seeking to roll out its "regional" business model across the rest of Europe.
It employs more than 2,900 people and operates 215 routes across Europe.