Looks like the TCR / Holborn area has gone bezerk as TfL have just tweeted the following.
Buses that serve Tottenham Court Road, Goodge Street and Holborn areas are subject to delays of up to sixty minutes due to heavy congestion.
Route 8 has reduced service, 1 in 4 buses serving whole route. Rest will start/terminate at Holborn or Bank. LU accepting bus tix in Zone 1
Route 25 has reduced service, 1 in 4 buses serving whole route. Rest will start/terminate at Holborn or Bank. LU accepting bus tix in Zone 1
Route 55 has reduced service, 1 in 4 buses serving whole route. Rest will start/terminate at Holborn. LU accepting bus tix in Zone 1
Route 73 is on diversion via Portland Place and Euston Road due to delays. LU accepting bus tix in Zone 1.
Due to the delays in Central London London Underground are accepting bus tickets in Zone 1, explain to station staff & they let you through.
I don't understand how the last one works because buses don't give out tickets any more. I suppose they could let someone with a bus and tram pass through but how do they handle people with non Z1 T/Cards that would normally use the bus but are instructed to use the tube? Would LU people really let you on the system for free?
While delays at TCR are not new it is unusual for TfL to tweet about such severe cuts to services although operators have part curtailed routes in the past.