Where can I find proper folk pub sessions in London, not open mic nights?

Years ago, when I worked in Dundee, I used to go to a weekly folk night at a pub called The George Orwell. It wasn’t a formal gig — musicians would gather around a table with fiddles, double bass, banjo, harmonicas and acoustic guitars, and people would just play together.

The atmosphere was incredible: cosy local pub, no microphones, and a mix of traditional songs alongside unexpected folk-style covers. I remember hearing AWOLNATION’s Sail played this way and it somehow worked brilliantly.

Since moving to London, I’ve found a few open mic nights, but they haven’t captured that same communal feel where musicians are playing with each other rather than taking turns performing.

Does anyone know of pubs, folk sessions or regular nights in London with this sort of atmosphere?

I’d happily travel across London if it’s something special.