It's complicated. The Union of the Left has a very good chance of forcing a "cohabitation" through a legislative majority. This would mean Macron would be forced to pick a Prime Minister from the left coalition and might not hold a majority. This union came about very quickly and will not happen on the right, as Macron and "Les Republicains" would not want to ally with the Extreme Right. It will be interesting to see what the "gouvernement" looks like in June.