BMI faces a legal challenge by the Unite union over claims that the airline has failed to honour a three-year pay award to staff.

Unite claimed, as a result, its 3,000 members at the airline have not had a pay rise for two years. The union, which is behind cabin crew action at British Airways, has instructed lawyers to begin action in the High Court.

Unite national officer Brian Boyd said: “Unite is lodging a High Court claim against BMI because the company owes its employees a long overdue pay increase.

“Staff agreed to defer the increase to help the company during difficult times but they are still waiting for the company to honour its end of the bargain. Lufthansa, which owns BMI, is a huge airline and employees need reward for their dedication and loyalty.”

A BMI spokesman said: “Constructive talks are continuing and discussions remain ongoing.”

The airline entered into a three year pay agreement with the union three years ago which meant staff would receive pay rises in 2007, 2008 and 2009, Unite said.

The first two rises were paid and the union said it agreed to defer a 4.75% pay increase, due in April 2009, until March 31 this year due to the economic downturn.

Unite claimed the carrier has not honoured the agreement to pay the third year of the deal.