French Prime Minister Michel Barnier used a constitutional tool to push through parts of his unpopular budget bill without a parliamentary vote, raising the prospect lawmakers could dissolve his government within a matter of days.

To survive the vote in the fractured lower house, Barnier needs Marine Le Pen's party to abstain, otherwise his government and the budget bill could fall, plunging France into a political crisis.

The far-right National Rally indicated in the strongest language yet that it could topple the French government as soon as this week, hours after Finance Minister Antoine Armand said his administration wouldn’t be blackmailed.

In a "dramatic move", the far-right leader gave Prime Minister Michel Barnier until today to respond to her National Rally party's demands and alter his government's budget plans, said Politico. There are fears in French financial markets that the fall of the government could "precipitate a eurozone-wide crisis".