French President Emmanuel Macron has thrown a wrench into the plans of the New Popular Front (NFP), a left-wing coalition including La France Insoumise.

In a letter to the French people, Macron effectively ruled out allowing a government that includes parties he deems outside the 'republican forces' to lead France.

This move comes as the left-wing parties, negotiating since Sunday evening, failed to agree on a Prime Minister to propose to the President.

Macron's swift action has caught the NFP off guard, as they were engaged in a race against time to form a government.

The President's call for 'responsibility' and appeal to 'overcome divisions' to form a 'national unity' government has further complicated the political landscape, drawing outraged reactions from the left.