According to Construction News
https://www.constructionnews.co.uk/...bn-rail-improvement-wishlist/10019078.article [paywall], TfL has approved a £3.6bn wishlist covering the rail improvements they think necessary in CP6.
The document which was input to the planning meeting which approved the wishlist is at
http://content.tfl.gov.uk/13-hlos-tfl-proposals.pdf.
In section 3.2, the document notes that:
As already noted upthread, this Initial Industry Advice is not a public document - which it was when CP5 was being planned for.
The TfL document excludes consideration of schemes outside CP6; these include Crossrail 2; thus section 4.2:
In section 4.3, TfL states:
A summary diagram of the proposals copied from the TfL document (which is public) is viewable at:
[url]https://markrogergregory.net/2017-04-14_05-44-08[/url][/QUOTE]
The two things for the SWML that are interesting from that is that a) the southern access to Heathrow is being seriously considered and b) the remodeling of Basingstoke and Woking Junctions are being pushed for by TfL (even though they are well outside of TfL's normal area of interest).