The Indian aviation ministry has put Air India Express’ plan to take on wet lease of four aircraft on hold until it reviews the decision of the country’s low-cost carrier board.

The ministry has taken the decision anticipating that the deal leasing planes with entire crew will severely affect the airline’s revenue.

The current fleet includes 21 Boeing 737s, of which four are on lease and two planes are grounded for regular maintenance by rotation.

The airline board decided to take four planes on dry lease and as many on wet lease to serve its routes.

The dry lease for four planes was extended to retain the figure of 21 planes, but employees opposed the decision to take as many planes on wet lease on hefty sum, according to The Times of India.