Wary of a public that has never really forgiven them for blighting their view with a skyscraper 40 years ago, Paris authorities narrowly rejected plans for a 43-storey triangular-shaped building on Monday.

The 180-metre (590-foot) Tour Triangle was supposed to go up in the southwestern corner of the city by 2017, but local lawmakers blocked the proposal by 83 votes to 78 in heated scenes at city hall.

Mayor Anne Hidalgo said she would launch a legal appeal against the vote, accusing councillors of displaying their voting cards in what was supposed to be a secret ballot.

"The law has not been respected," she said.

Her deputy in charge of urban architecture, Jean-Louis Missika, said either the votes that were displayed publicly would be declared void, or the entire vote would have to be re-done.

The Triangle tower project was supposed to create 5,000 jobs with construction costs put at 535 million euros ($670 million) in 2011.

But many lawmakers will have been thinking of the scorn that is still directed towards the Tour Montparnasse -- a brown carbuncle opened in 1973 that remains the only skyscraper in the city centre and has made it all but impossible for developers to win approval for future high-rises.

Paris imposed a height limit of 37 metres in the wake of the uproar over the 210-metre tower in Montparnasse -- which was accused of ruining both the view and a once-beloved artist district.

City developers later struck a compromise with critics by quarantining high-rise buildings in the La Defense business sector just outside the centre.

'A pyramidal monument'

But the rules changed in 2010 when the city decided to allow apartment blocks up to 50 metres and offices up to 180 metres in areas near the ring road.

In July 2013, it gave initial approval to the Tour Triangle in the Parc des Expositions. Environmentalists and aesthetes were immediately up in arms.

They had formidable support, including from Norman Foster, the celebrated British architect behind several skyscrapers including London's "Gherkin".

"I don't see what Paris needs with a skyscraper," he said at the time.

The UN's cultural body UNESCO also waded in, warning that new towers would threaten the landscape of "one of the few remaining horizontal cities".

The prestigious Swiss team behind the project, Herzog and De Meuron, rejected the criticism, saying the Triangle was "beautiful".

Mayor Hidalgo backed the scheme despite polls showing a majority of Parisians opposed it.

Her deputy, Missika, called it one of the "future centres of Greater Paris" and a dynamic symbol of its ability to revitalise itself.

"It's not a tower, it's a pyramidal monument," he said.

But Michel Carmona, an expert in the Haussmann style in which Paris was designed in the 1800s, said that such sudden breaks with the past were "a taboo" for Parisians.

"The unity of the Paris landscape is the envy of the world. It's a test of talent for an architect to work within the Parisian template without breaking it," he told AFP. "Will the Tour Triangle attract foreigners? Not a chance."