A month-long consultation into proposals to redevelop London's iconic Sloane Square has begun.
Opponents said the plan will cause longer traffic delays
The plan to create a four-lane road and two piazzas in the west London square have drawn opposition from celebrities including broadcaster Sue Lawley.
Members of the Save Sloane Square group said the scheme will ruin the area and cause more delays on surrounding roads and have devised an alternative plan.
Kensington and Chelsea said the plan makes better use of the public space.
Ms Lawley has previously said the move would separate the "very elegant" and "iconic" west London square.
Actor Rupert Everett and singer Brian Ferry are also supporting the campaign.
Lord Grantley, of the Save Sloane Square group, said their plan would preserve the central island and retain key monuments in their "rightful settings".
Councillor Daniel Moylan maintained the council plan would greatly improve the square.
"Sloane Square deserves to be among the best and most elegant public spaces in London," he said.
"The council's well thought-out plans will make the square a much more pleasant space to be for residents and visitors alike.
"No one wants to spend time sitting on a busy roundabout for a coffee or lunch."