Strange that you should bring up the Channel Tunnel, Prophead. That project is the poster-child of broken promises to Regional UK and a large part of the reason that political promises on infrastructure are so comprehensively distrusted in the regions. Major cities across the UK were promised direct services through the tunnel ... until it opened! Then they decided that regional services "wouldn't be viable" ... without actually trying them first, of course! And the 'for London only' mindset persists. The proposed link-route from HS2 to HS1 (and the tunnel) was axed to save just 2% of the overall project cost. That shows what politicians really think about linking the Midlands, North and Scotland to markets on the Continent. Contempt.
Now, about those promises of all manner of goodies for the regions if R3 does get built. I'm sure we can all rely on Westminster to make good on them ... can't we?
No MP's or civil servants were subjected to public disgrace (made accountable) for their roles in the scandal outlined above.