One of Northern Ireland's top manufacturers has said a Stormont minister has missed a huge opportunity to create local jobs.
In a letter to the Belfast Telegraph Dr William Wright - co-founder of the global bus builder Wrightbus, responsible for the famous 'Boris bus' in London - has called for Regional Development Minister Michelle McIlveen to intervene after a Belgian firm won a £19m contract to build 30 new buses for Belfast.
He said it was "extremely unfortunate that this contract has left Ballymena and Northern Ireland", and that the minister needed to "reverse this decision".
The company said it was "bitterly disappointed" to lose the chance to build 30 new vehicles for the new Belfast Rapid Transit (BRT) system to rivals Van Hool.
Dr Wright challenged a statement by the DRD saying that Wrightbus had not made the correct type of buses needed for BRT in seven years.
The Unite union called the decision "inexcusable" at a time when the manufacturing sector in Northern Ireland was struggling.
A DRD spokesman said the Ballymena-based company "had gone through the same standard procurement process everyone had to go through".
"We award the contract to the most economically advantageous tender that takes into account the cost," he added. "Wrightbus have seen the benefits of the same rules when they're applying to other countries and successfully delivering buses in London and Las Vegas.
"We're bound by European legislation and we would be penalised if we didn't go through this process."
He said the DRD wanted tram-like bendy buses for BRT, but Wrightbus had submitted a design similar to its double decker London buses. Dr Wright refused to accept that the design by Wrightbus was unsuitable, pointing towards the model's previous success in Las Vegas.
He said that this made him wonder if Van Hool was simply "asked to submit a redesign at a competitive price".
He said he also wanted assurances that the hybrid electric vehicles that Van Hool was producing would be of a sufficiently high standard.
"I am concerned as to what type of batteries this vehicle will use, as some batteries only have a lifetime of two years," Dr Wright said.
"More and more media coverage is given to the NO2 and the damaging effects of particulate matter. This causes around 29,000 deaths in the UK each year, as the latest figures from COMEAP (Committee on the Medical Effects of Air Pollutants) estimate. What thought has been given to this?"
He argued Wrightbus was producing "six hybrid buses per week, and our depth of knowledge and experience is second to none".
The DRD spokesman it was confident the Van Hool fleet would meet expectations.
"Hybrid technology has been going for quite a few years, so in terms of carbon emissions, the new buses we've ordered would be quite comparable to what Wrightbus were offering," he said, adding warranty for the batteries is "about five years, and there's been no problems with the Belgian company's previous models".
Despite its disappointment, Wrightbus said it "respected DRD's ultimate decision in this instance, and we hope that in future more innovative designs are given consideration".
Local companies have not been entirely excluded from working on the BRT - Larne firm Road Trucks Limited will provide maintenance and specialist support for the new system.
DRD has said further contracts will be awarded over the next few years which will add an estimated £50m to the local economy.
These include the delivery of 20 new vehicles, which will provide feeder services to the new system from east and west Belfast, as well as construction work on the new routes and depots for the vehicles.
Under EU regulations, the contracts will again be open to outside competition.