Birmingham MP John Hemming has won an unlikely supporter in his campaign to become Liberal Democrat leader - a Black Country Labour MP.
Tom Watson (Lab West Bromwich East) has pledged his loyalty to Mr Hemming (Lib Dem Yardley) and urged Lib Dem MPs to back him.
The tongue-in-cheek endorsement, which appears on Mr Watson's website, includes references to married Mr Hemming's affair with his researcher, Emily Cox.
It came as Lib Dem President Simon Hughes confirmed he is to be a contender in the leadership battle.
Mr Hughes said the party faced its "greatest ever opportunity" and that he offered the ambition, enthusiasm and passion to realise it.
He is making his second attempt at the leadership, after being beaten by Mr Kennedy in 1999.
Mr Watson, a Government whip, mocked Mr Hemming on his website by calling him the "Libido" MP.
Mr Watson said: "I hereby pledge my support to Libido MP, John Hemming.
"Colleagues, I urge you to send your nominations to party officials. If you know any Lib Dem MPs, John needs seven of them to nominate him in order to get on the ballot paper. So far he has three.
"I'm going to find out if a nomination from me will count, so he needs at least another three MPs to go forward. We have the genesis of a mass movement here."
But Mr Hemming has revealed he may back out of the leadership contest after all.
He was one of the first candidates to declare after Mr Kennedy resigned.
Sir Menzies Campbell, the party's Foreign Affairs Spokesman, was also an early entrant in the leadership race.
But since then, more candidates including Home Affairs spokesman Mark Oaten, Mr Hughes and Economic Affairs spokesman Chris Huhne have announced they will stand.
Mr Hemming said: "I need to ask members whether it is right for me to continue to progress my candidature."
He had stood to ensure there was a contest and prevent any candidate, such as Sir Menzies, being elected unopposed, he said.
Mr Hughes formally announced his intention to stand at a press conference in London's swish riverside Oxo Tower.
He pointed out he had been elected by the party's 73,000 members 16 months ago as president.
He went on: "What I offer is my ambition, my enthusiasm and my passion. What I offer is the experience of many years in Parliament and campaigning around the country to motivate people to join us.
"I believe that we now have our greatest ever opportunity. I believe that I have the ability to unite the party, to motivate the party, and to bring us as a party in the mainstream of British politics to greater electoral success.
The party had made "right and courageous judgments" on Iraq, Europe and global injustice, and had "robustly defended" civil liberties and championed the environment, he said.
"We now have to demonstrate that we can make the right judgments over other issues which matter to the British people: their finances; their homes; their pensions; their security."
Bookmaker Ladbrokes swiftly installed Mr Hughes as 5-4 favourite to succeed Mr Kennedy.
Sir Menzies Campbell was a shade behind at 11-8, newcomer Chris Huhne was put at 7-1 and home affairs spokesman Mark Oaten was trailing on 9-1.