Hi Kev, usually the ends of copper pipe are flared to prevent rubber fuel line from coming off once they have been clamped up with a jubilee type clip.
I used a basic type of flaring tool on my 10mm copper pipe to ensure the rubber fuel line will not come adrift.
If you are going to use this type tool on it be careful as with mine if I flared the pipe fully it was almost impossible to get the rubber fuel line over the end, as you have already stated it is not overly flexible.
Another option which I think is acceptable at the SVA test centres is to double jubilee clip the pipes.
Personally I'd rather flare the ends, much safer!