The candidates, spanning the hard left to far right, agreed that France was facing economic trouble, at a debate organised by the country's employer's federation MEDEF.
But at Paris's Roland Garros complex, more used to hosting clashes between top tennis stars than between politicians, they differed wildly over how to combat the country's problems.
Marine Le Pen, seeking the presidency at her fourth attempt and riding high in the polls, announced her far-right Rassemblement National (RN) party would present a €125 billion cost-cutting plan and acknowledged there was a "general consensus on the seriousness of the situation".
But hard-left leader Jean-Luc Mélenchon urged business leaders to "raise wages" to prevent France from "falling into recession" and slammed "tax giveaways" under Macron which he alleged equalled the sum of the entire deficit.
Centrist hopeful Edouard Philippe, a former premier under Macron, accused Mélenchon of seeking to "burn" France's debt and take steps that would "result in France being shut out of the banking system".
The debate comes less than eight months ahead of the 2027 election to choose France's new leader, with centrist incumbent Macron having served the maximum two consecutive terms.
Given France's two-round election system, there is growing concern that a plethora of candidates on the centre, centre-left, centre-right and right could split the moderate vote in the first round.
This could send Le Pen and Mélenchon, who, like his far-right rival is making a fourth crack at the presidency, into a run-off devoid of the traditional parties.
A new poll this week by Ifop-Fiducial projected that hard-left Mélenchon could make the second round against Le Pen, who is far ahead in polls for the first round.
On the centre, two of Macron's former prime ministers, Philippe and Gabriel Attal, are both campaigning hard, with neither wanting to give way for the other.
The campaign on the left has been galvanised by the entry of the centre-left former commentator-turned-MEP Raphael Glucksmann, who intends to take part in a primary with the Socialist Party in October to find the best candidate.
Glucksmann also took part in the debate, along with Bruno Retailleau of the right-wing Les Républicains (LR) and Greens leader Les Écologistes, Marine Tondelier.
Referring to Attal and Philippe, Glucksmann quipped: "It is actually quite surprising to be lectured on debt by two of Emmanuel Macron's former prime ministers."
Days after Macron agreed with the Saudi crown prince on a €6 billion deal for theme parks outside Paris, Glucksmann added: "I do not want the fate of my country to be a theme park for American tycoons, Russian oligarchs, Chinese Communist Party dignitaries, or Gulf emirs."
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