Iain Dale says he has checked and Greg Dyke was a serious proposition as the joint Liberal/Conservative Mayoral candidate.

Neither the Tory or LibDem high commands have so far managed to find the candidate to take on Ken. Combined perhaps they can do it. Dyke has technocratic ability, a combatitive personality and a track record. He is only a recent convert from Labour to LibDem, so sticking a blue and yellow rosette on him would be a shock. Not least for the activist base who might not be too keen…

UPDATE : The story is true, Greg Dyke confirms an approach was made, which he turned down.