France is one of the most powerful members of the European Union (EU) but it has a huge public debt – twice as much as the limit set by the EU.
As a result, Mr Barnier used special powers to force an unpopular budget through parliament on Monday – to try and reduce the debt – without MPs having a vote.
This angered lots of MPs, and two different political parties decided to trigger a debate on the future of the French prime minister, which was followed by a vote on whether or not to remove him.
Mr Barnier defended pushing his budget through without parliamentary approval, saying he worked with both chambers of parliament to develop the document.
A total of 288 votes were needed in order for the government to collapse – and 311 votes were cast in favour of getting rid of Mr Barnier, just three months after he was appointed by President Emmanuel Macron.
France now risks entering a new year without a government or a budget.