That is correct. Recently a useful link was posted by japitts, one of the forum VIPs, which was at the bottom of this page.
https://www.virginmedia.com/help/diversionaryworks
Untested, or at least no feedback about it on here AFAIK, but you could also try there.
If you have read the other/earlier scary posts, you'll probably be aware that a survey fee of £240 usually seems to be required before VM present you with a huge estimate for the work.