Mr Mellor, whose previous majority was a fragile 7,526, won 17,108 votes last night. But this was a crucial 3,000 short of Mr Colman's 20,084. It was, however, Sir James Goldsmith, the leader of the Referendum Party, who chose to stand against Mr Mellor, who he had it in for. Sir James passed all his own expectations and secured 1,518 votes, to the sheer delight of his proud family.
Mr Mellor began his speech graciously - every bit the honourable loser. He wished Mr Colman every success before launching a savage attack on Sir James, the majority of his votes are understood to have come from disaffected Tories.
He described Sir James's total as "derisory". "He's got nothing to be smug about."
With that, Zac, Sir James's 22 year old son fought back on behalf of his father. "Off, off, off!" he screamed, chorused by his relatives. But Mr Mellor moved up a gear. "And we have seen tonight that the Referendum Party is dead in the water. You can get off the platform and go back to Mexico knowing your attempt to buy off the British political system has failed."
Speaking to television crews afterwards, Mr Mellor went further. He ordered Sir James to go back to his hacienda "Having folded almost as abysmally as his son in Pakistan."
Asked about his future plans, Mr Mellor said that it was at times like these that he was thankful for his other interests so that he could support his family. "Thank goodness there's some other shots in my locker," he said, cheering up momentarily. "You may not have heard the last of me."
Mr Colman was low-key in his acceptance speech. "This is a great victory for Putney and a great victory for new Labour, a new beginning for Putney and the UK and a new age of achievement," he began.
He promised to "always keep faith with the Putney constituents" and to continue to improve upon Mr Mellor's service to Putney. "There's so much to do with 18 wasted years, 18 wasted years," he said.
Mr Colman, 53, is presently Labour leader of Merton council, the adjoining borough. Like Sir James and Mr Mellor, he is also a wealthy man. He was a co-founder of Top Shop before going into politics. He is married with five sons and one daughter.
The Sportman's Alliance - whose symbol was a giant papier mache toe and slogan "Mellor Sucks. Anything But Mellor", was last night celebrating its 90 votes. The theme of their party was reiterated by Sir James's entourage of relatives - his wife, Lady Annabel, his daughters Isabel, 42, and Jemima, 23, his brother, Teddy, 69 and his son Zac. Riotous heckling almost matched Mr Mellor's tirade of abuse.
With reference to Mike Yardley, candidate for the Toe Party and Sir James standing beside him on the platform, Mr Mellor said: "it should be noted that the noise being made in this hall has nothing to do with serious candidates but comes from the Referendum Party and the supporters of the gun lobby."
Mr Mellor said that he was ill-equipped to pay them just tribute. "As far as some of the rest of the candidates assembled here, what can I say? That even being a fellow of the Zoological Society didn't prepare me for this."
Lady Cobham with whom Mr Mellor now lives, dressed in an optimistic electric blue suit, smiled throughout.