London's elite law firms are still struggling to bring more women into their top ranks, perpetuating a gender gap that threatens to spark criticism from corporate clients, new research reveals.

Statistics compiled by The Lawyer magazine show women make up an average of just over 14 per cent of the partnership at the UK's four largest "Magic Circle'' firms - Clifford Chance, Linklaters, Freshfields Bruckhaus Deringer and Allen & Overy.