This is where the £18m came from:
https://polaris.brighterir.com/publi.../story/xlm4dpr
Stobart Air has played a fundamental part in the growth strategy for London Southend Airport. As previously announced, Stobart Group incurred net costs of £18.0 million in route development and marketing for the airport. This expenditure represents the development of routes operated under the UK Flybe franchise operation (UKFFO). Demonstrating route viability and building customer awareness was central to securing a milestone agreement with Ryanair that will allow us to accelerate the growth of the airport.