The game legal "ping pong" between th Rabbanut and its adversaries such as Hashgacha Pratit might soon come to an end, if this new law proposal will pass.

A law proposal submitted by a number of MKs from various parties, including MKs Yoav Ben Tzur (Shas), Moshe Gafni (UTJ), Betzalel Smotrich (Habayit Hayehudi), Menachem Eliezer Mozes (UTJ), David Amsalem (Likud), Miki Zohar (Likud) and others, calls for not allowing a business to present itself as kosher even just by presenting some sort of demonstration that it is kosher even without using the word "kosher" and even if they explicitly say they are not certified by the Rabbanut.

This is to support the Rabbanut as the law says only the Rabbanut (along with the IDF Rabbinate and local city rabbis) is authorized to certify kashrut. They say this will protect the consumers from fraudulent kashrut claims.
source: Kikar

I do suspect that the ping pong game won't actually be finished. Even if it passes, it is hard to imagine that this won't be shot down by the Supreme Court. I cannot see how anyone can make it illegal to imply kashrut. It is way too vague. What one sees as an implication of kashrut, another will see as benign. And even if it does pass and does not get shot down, Hashgacha Pratit, and others, will probably find a way around this too.

Instead of continuing to try to protect their monopoly, they should see the writing on the wall and improve their system so that people will be proud to use their services and people will be proud to rely on them and the good service they provide for a fair price will be enough to keep the competition at bay. These regular lawsuits and law proposals for every new workaround by Hashgacha Pratit seems like desperation.

Rav Yaakov Ariel, rav of Ramat Gan, has said that the alternate hechsher known as Hashgacha Pratit cannot be relied upon for kashrut. He also said about its founder, Rabbi Aaron Liebowitz, that not every rav can give kashrut certification, and definitely not someone who is destroying kashrut.

He also said that the various Badatz hechshers generally only go into a place and declare it kosher after the Rabbanut has already done so. The Badatz cannot be relied upon in a place where they declared it kosher without first the Rabbanut doing so, according to Rav Ariel.
source: Srugim

So, according to Rav Ariel, Hashgacha Pratit is just like any other hechsher - just like any private Badatz, for example. According to Rav Ariel, only the Rabbanut can give kashrut and be trusted, and no private hechsher can.

Legally that is the case, and will be so even more so after Shas's new law will be passed in the near future. Halachically that is not the case.

According to halacha all you need is to trust the person telling you it is kosher. There is no concept of hashgacha, private or public. I can trust the Badatz privately, without needing the Rabbanut, from a halachic perspective. I do not even need the Badatz if I trust the owner of the restaurant, or if he hires a private mashgiach that I trust.

That being said, as I have said before, I do not really get how Hashgacha Pratit works. At best it is like any other private hechsher, as Rav Ariel said, and one can choose to trust them or not. In reality though they are trying to do things differently. They have some system of volunteer supervisors, but for the most part people are relying on the word of restaurant owners who are largely not religious and whom they generally do not know personally. Can they be trusted? I don't know. Anybody and everybody can decide for himself or herself, but to me it seems spurious. Even though in theory I like the idea of going back to the system of trust that kashrut is really based on, I do not see how it can work the way it is working.