Carols at Southwark Cathedral

Hi there, we're in London for Christmas for the first time this year and are hoping to go to a Christmas carol church service on Christmas Eve. Does anyone know how busy the afternoon family service at Southwark Cathedral(around 4pm) on Christmas Eve gets? Would we need to pitch up quite early? Thanks so much!

the Southwark cathedral services are always rammed to the rafters. my advice get there early. last year the 6.30 one just before xmas was full 45 minutes before kick-off

Thanks Paul, will get there early!