To re-iterate, the RMT is prepared to accept DOO on London-Brighton services.
It's the East Coast (Brighton to Eastbourne / Hastings) and West Coast (Brighton to Worthing / Chichester / Portsmouth) services which the RMT is most concerned about. SASTA intends to put DOO in across the entire network (aside from the London-Uckfield line, we're told), even though the stations along those lines don't have the neessary technology to safely allow the driver to make the call as to when to close the doors. Nor do SASTA (who run those stations) have any intention on putting that technology in.
Unless, of course, the drivers do what the TOCs own safety reports suggests - leave the cab, and check down the platforms themselves.
It's a separate issue, but dwell times on the stations will increase (even 1 min per station has a knock-on effect), leading to further delays and cancellations back down the line.
I'm curious - when were the RMT appointed the final arbiter on passenger safety?
I would have expected it to be someone like, oh I don't know, the Rail Safety and Standards Board?