This week the British government passed another roadblock on its Brexit journey when the bill to trigger Article 50 was debated in the House of Lords.
The overall net effect of the UK leaving might be neutral but in any change so massive there are bound to be winners and losers and Ryanair's CEO Michael O'Leary is convinced that the effect on air travel into and out of the UK will be negative. Is he just scaremongering?
O'Leary believes that a hard Brexit will jeopardise the chances of Britain remaining a member of the European Open Skies agreement. That is true because automatic membership, just as of the single market, is reserved for members. The European Court of Justice (CJEU) is the ultimate authority for European Open Skies. Britain's exit would mean no longer accepting its authority so, as is the case for any trade agreement, this would have to be negotiated independently. Some kind of agreement will no doubt be reached because, as our politicians regularly remind us, access to the UK is important for Continental countries.
But that is logical and given the nature of political agendas there are many shades of grey that any agreement could take.
Ryanair's Open Skies status is unaffected because it's an Irish company but once UK membership ceases, it will no longer have the automatic right to operate there. easyJet's problem is the reverse. The addition of Barcelona and Venice a year ago took its total of European bases to 28. After Brexit it will no longer have an automatic right to its bases in places such as Germany, Italy, Spain and France.
While easyJet is known to be looking at setting up an EU-based operating company to maintain the status quo, Ryanair is not expanding UK operations and is openly questioning their viability post Brexit.
IAG is registered in Spain and plans to launch its low-cost operation from Barcelona. It could also move its headquarters and more of its operations to Spain to continue to have unencumbered access to destinations.
This will soften some of the consequences from the UK no longer being part of Open Skies. No doubt a new bilateral agreement will be negotiated in due course but the EU-US Open Skies agreement took years to negotiate.
But will there actually be any effect on corporate travel?
It's worth remembering that before the US-EU Open Skies agreement was signed in 2007 the US-UK bilateral in place gave access to Heathrow only to American Airlines, British Airways, United and Virgin Atlantic. Open Skies opens the doors for everyone — a bilateral might not, especially given the protectionist times in which we live.
For example, Norwegian established an Irish operation to curtail the long negotiations that would be required if it had been merely a Norwegian carrier. Despite this, it took three years to gain approval because of the US airline industry lobbying to resist a low-cost, long-haul carrier.
The UK is about to see how special its "special relationship" is. One of the first industry leaders to meet with President Trump were the CEOs of United and Delta (the American CEO had another engagement) to argue the case of what they perceive to be unfair foreign competition.
One of the President's campaign pledges has been to protect American jobs and few labour interest groups are more vocal than pilots and other airline workers and perhaps for good reason.
An agreement will happen but there are strong odds that there will be less competition and therefore less capacity over the Atlantic. That may very well translate into higher air fares for UK plc.