Insanity. It can't be real as even he isn't that stupid.
"The eventual successful project, organised by Eurotunnel, began construction in 1988 and opened in 1994. Estimated to cost £5.5 billion in 1985, it was at the time the most expensive construction project ever proposed. The cost finally amounted to
£9 billion (equivalent to £22.6 billion in 2023)."
"The Channel Tunnel, is a
50.46 km (31.35-mile) undersea railway tunnel, opened in 1994"
"The shortest distance (air line) between New-York and London is 3,461.34 mi
(5,570.48 km)."
Treating it seriously for a moment, it'd have to hit Ireland first, that's after any deep sea problems including undiscovered trenches/channels, the tectonic plate boundary, and the small matter of getting enough fresh air pumped down the thing to keep anyone crazy enough to risk it alive.
Maybe it's why he fancies being a trillionaire, because I'm not sure... ~ well, let's give it a whirl at scale.
50km ~ £22.5b
~5,550km = £2497.5b
That's very nearly 2.5 trillion pounds sterling. Conversion time. Todays rate makes it 3,105,624,775,000.00 us dollars. So just over 3.1 trillion $ dollars.
Need to sell a few more of those exploding batmobile trucks.
[Edit: This is a very rough estimate, the tunnel was being dug from both sides, and met under the water. Cooperative. At a rate of conversion at *111 there's a multitude of digging issues besides geological to overcome and budget for.]