Arthur Figgis wrote:

- If passengers from south of Balham aren't enough to fill the trains,
consider extending south of Morden. I think there was once a plan, a long
time ago, to take over or share the railway to Sutton. Another option
would be a smidgen more tunnel and the eating of the railway branch to
Chessington.

Wasn't the Wimbledon - Sutton line built by the railways as a blocking
move to prevent the underground being extended to Sutton?

I thought it was a joint venture that only saw half come off.