Conservative Boris Johnson is leading the race to run London as counting continues.
Labour rival Ken Livingstone is trailing behind on first preferences after a bitter campaign that has seen the two men clash furiously in public and in private.
Liberal Democrat Brian Paddick faces the embarrassment of potentially being pushed behind into fourth or fifth place as the Green's Jenny Jones currently stands in third, while Independent Siobhan Benita is close behind him.
Although election organiser London Elects is not releasing precise figures for ballot papers counted, graphs on its website show a clear advantage for Mr Johnson in the first round of the mayoral contest. If no candidate takes more than 50% of the vote it will go to a second round.
The Conservative candidate's standing, however, is not being replicated by his party in London.
Labour is ahead in the vote for London-wide Assembly candidates followed by the Tories, while the Lib Dems are in fourth place behind the Greens.
London Elects' graphs put Labour ahead in eight of the Assembly's 14 first-past-the-post constituencies, with Tories on course to take the other six.
This would mean a two-seat loss for Conservatives and the Assembly looked almost certain to remain under no overall control.
In the five seats declared so far, four were Conservatives and one Labour.