Boris Johnson has promised that work on the Malden Rushett crossroads will finally begin in September this year.
The junction is a major route from London to the M25, passing Chessington World of Adventures and regularly sees large tailbacks, with drivers reporting 'unsafe'
Speaking at a Mayor of London question time last night at Richard Challoner school he held his head in his hands and said: "I've been briefed to the eyeballs on this".
The Mayor at last night's Question Time in Richard Challoner School, Old Malden
In 2011 residents were told budget cuts had delayed a scheme to revamp the junction.
The new plans were unveiled in June 2013 expected to begin early this year.
Malden Rushett Residents' Association chairman Beryl Gibson said earlier this year when works were delayed yet again: "The residents will be deeply disappointed.
"Obviously they've got to get it right and we want it right."