The Yellow Vests loved the idea of citizens being able to call referendums, so among the minimal pandering by Macron last year was adopted the possibility for members of parliament to launch official petitions to add items to the agenda of the National Assembly. The threshold is 10% of the voting population so over 4 millions signatures as of now. It's pretty extreme and probably was a guarantee it would never be used. Macron mused about lowering it to a million alongside his big constitutional reform he hoped for, but the latter has been shelved indefinitely.
The first of such, to force a second examination of the projected privatization of ADP ("Paris Airports" which also holds shares in many airports worldwide), was launched soon after and will expire a month from now.
It will never make it to 4,5m signatures but collected a million still. Opposition MPs, notably the Communists, are trying to leverage this into debates.