Bad link.
I assume it's this article here:
https://www.newcivilengineer.com/lat...012673.article
which in turn recounts the comments of Andrew Haines, CAA Chief Executive, made at NCE's Airport Conference back in May:
The real warning shot came from regulator Civil Aviation Authority chief executive Andrew Haines. Government making a decision between Heathrow and Gatwick is just “the beginning of the beginning”, he warned. The big challenge, he said, will be to regulate an investment of this size: whether it is Gatwick and its £8bn plans or Heathrow and its £22bn plans.
“There is no track record of regulation being applied to something of this size,” he said.
It is genuinely unprecedented for there to be a major multi-billion infrastructure investment of this scale with absolutely no government guarantee or assistance. The nearest to it is Hinkley Point C. That even comes with government guarantee and look where that’s at. The nearest transport project to it was the Tube PPP. And look how that ended up. His point had resonance.