The ushers must prevent mechitzas from being brought down to the plaza, though if force is needed, they have no such authority and police must be called in.

sources: Kikar, Kol Hai News

Obviously this is in light of recent incidents at the egalitarian plaza, and also with Tisha B'Av coming and the memories of the incident there on Tisha B'Av last year.

I am not quite sure if this has the status of executive order and what the actual law is, what authority this letter has. Considering Avi Maoz of Noam party has said he is going to bring mechitzas down there tonight I am guessing we will soon find out.

To exaggerate a bit, a rule saying "no mechitzas allowed" is reminiscent of the British Mandate... but the truth is this areas was designated for egalitarian prayer and the rule is only needed because of the provocations caused by other people, similar to the rule at the Kotel of not bringing in Torah scrolls from the outside...