Campaigners are outraged that Barnet Council is refusing to support proposals for 24-hour traffic lights at Stirling Corner.
A statement from the Conservative-led London borough said it was “not pushing for any changes” at the roundabout, which links Barnet and Borehamwood.
But Labour councillors from Barnet have vowed to continue to back the new safety measures at the “dangerous” junction.
Councillor Anita Campbell (Labour, Barnet Underhill), said: “Are the council waiting for another disaster at the dangerous roundabout to make them change their minds?
“This is ridiculous. It is a dangerous racetrack and it is time for action to be taken.
“If they are going to stick to those views, I too will be standing my ground and I should hope that my fellow councillors do the same.”
Last week, London Labour Assembly Member Andrew Dismore launched a safety survey into the area, which was well received by campaigners in Hertsmere.
The traffic lights currently operate from 3.30pm to 6.30pm, but campaigners from Borehamwood believe round the clock lights would reduce help reduce accidents.
The area has seen countless car accidents over the past few years, including one fatality in February this year.
Leader of Barnet Labour group, Alison Moore, said: “It is outrageous that this situation has been allowed to drag on for so long.
“We have always said that this junction needs a change and I am glad we finally have an Assembly Member able and willing to assist in this”.
The group sent a letter to the leader of Barnet Council, Richard Cornelius, earlier this week in a bid to persuade him to look afresh at the problem and support Mr Dismore's campaign, and are awaiting a reply.
Transport for London (TfL) told the Borehamwood Times last week it saw no “no need” to install round the clock traffic signals at the roundabout.
Barnet Council’s statement added: “Last year TfL carried out a trial suspension of these part-time traffic lights as part of a London-wide initiative to reduce the number of signals across their road network which did not particularly impact traffic on the Barnet controlled arm of the junction.
“Stirling corner is a major junction where changes in traffic movement would need careful consideration.
“The council would therefore expect any review to consider the impact on traffic flow as well as the safety of all road users.”