The North West London Eruv has been "breached" due to the inclement weather.
Orthodox members, who are allowed to carry certain items within a marked area during Shabbat, are being told: "not to assume the eruv will be up" this weekend
People who normally carry certain items such house keys, prayer books and handkerchiefs within a strictly enclosed area, will not be able to carry anything.
Dr Daniel Ben-ari, who is Orthodox and lives in Hendon: said “Basically it’s a return to the pre-2003 set-up before we had eruvs: everything has to be thought about: can a guest who needs to bring a baby in a buggy still come?
"You have to make sure your tallit is in synagogue before Shabbat or otherwise must wear it to synagogue.
"Keys need to be placed on a shabbos belt, not put in the pocket.
"The danger is people will forget, so hopefully Rabbis will remind people not carry anything home, lest they forget. It reminds me how much more difficult things were without one.”
The North West London Eruv sent the following "urgent message" to all Orthodox synagogues in London:
"Due to the inclement weather there are several breaks to the eruv which are in the process of being repaired.
"In view of the expected continuation of adverse conditions it is advisable NOT TO ASSUME the eruv will be up over the coming Shabbat."
An eruv is an area within which observant Jews can carry or push objects on the Sabbath, (which lasts from sunset on Friday to sunset on Saturday), without violating a Jewish law that prohibits carrying anything except within the home. There are over 200 eruvs (or eruvim) in the world.
An eruv must be 'completely enclosed' by boundaries that conform to Jewish law. The North West London eruv has been recognised as valid by the London Beth Din - the Orthodox Jewish religious court.
This allows people to carry items they would normally only carry in their home. The North London Eruv was formed in 2003 and benefits thousands of Orthodox people.