I will just reiterate, it is illegal to carry a knife in a public place without good reason, apart from a non locking knife with a blade less than 3 inches.
The good reason for doing so is up to you to prove, it is not illegal to carry a knife in your car, despite it being defined as a public place, for example if i went to Tesco's( a shop), and bought some knives it would not be illegal for me to take them home in my car, however if I left them in my car for a few days and was stopped for speeding on my way to work, that could well be a criminal offence, as there would be no logical reason for me to have them in my car.( unless there was a good reason as defined under the law, for EG: I was a cook and the knives were tools of my trade, etc) which i would have to prove.
Which gives you the defence under section 139 of the 1988 Act. Without that good reason the offence is complete.
To the letter of the law, if you have good reason to have that knife with you in the car (which whether we like it or not is considered to be a public place until it is on private land) then you are not breaking the law by having it on your belt or in your pocket while you nip into the garage/Co-Op or whatever. In other words, you had it with you in a public place in both scenarios. There is no distinction in law .
I can't understand anyone who would advise anyone to carry a knife into a garage, or their local co-op,
I didn't. I specifically said it wasn't a good idea, and that you should apply common sense and leave it in the car. However, if you have a good reason to have it with you in the first place, then it doesn't matter whether it's in your belt, your pocket or the car. The defence of having a good reason is sufficient for you to avoid conviction. I emphasised the bit about no distinction in law so that I could move onto the next paragraph which you have chosen to exclude, which was the bit where I said it wasn't a good idea as it would cause concern.
Incidentally the only reason it was put into Law your car was a public place, was it allowed the Police to search it without a warrant.
You'll be able to point out where it says this in law then? Think about it logically. If the police are empowered to search a car without warrant, it would be for evidence of an offence, in this instance a bladed or pointed article. If having it in the car (without good reason) was legal, then it wouldn't be evidence of an offence would it?