France's debt rose by €202.7 billion to €3.3 trillion last year, accounting for 113% of GDP, according to the official statistics agency. Eric Lombard, France's economic minister, has acknowledged that this is a threat to France's financial stability.
My understanding is that it’s not a new tax, but a 20% minimum income tax for high earners. It’s a limit on how much income tax optimisation high earners can do.
Given the income tax rate in France, and a quick calculation, a single person earning €250000 should have a base income tax rate of ~35%. This is without any tax rebate, without any tax optimization.
So high earners who aren’t doing lots of tax optimisation should already have an incoming tax that’s higher than 20%.