Kate Moss and Lily Allen had to be separated after a dramatic row over Courtney Love on Tuesday. The pair got into a heated debate at London's The Groucho Club when Lily attacked Courtney for her feud with Kelly Osbourne and Kate angrily defended her friend saying she was a "great woman". A source said: "The trouble started when the pair met at the Groucho. Lily ran up to Kate, but after chatting amiably for a while she brought up the subject of Courtney and a row that had blown up between her and Kelly Osbourne."She was ticking Courtney off in a light-hearted manner, but you could tell Lily meant it."Kate certainly got that impression because she leapt to Courtney's defence. Kate's intensely loyal and told Lily that Courtney was a great woman."Lily begged to differ, but luckily at that point staff noticed tempers were flaring and directed Lily and her friends to a separate lounge on a different floor."In July, Lily, 22, and Courtney, 43, fell out after the 'Smile' singer wrote on her blog that she could understand why the rocker's late husband, Nirvana frontman Kurt Cobain, shot himself.Lily insisted her website had been hacked, but tensions between the pair were strained again when she had to intervene to stop a fight erupting between Courtney and her friend Kelly at London's Punk club.Kelly reportedly wanted to confront the rocker about her ongoing feud with her mother Sharon Osbourne.