On 8 Oct, 23:13, MIG wrote:
On Oct 8, 10:25 pm, "Paul Scott"
The only remaining possibility would be to start tunnelling south of
the Thames and replace London Bridge and Cannon Street with new
underground stations. It could be called Crosslink or Thamesrail or
something.

Oddly enough, one of the Thameslink 2000 route options was a huge
tunnel under the Thames from just east of London Bridge to Farringdon.
It would have been enormously expensive, and got in the way of the
foundations for the Shard.