No. Butterfly, double edged, ejector, flick, push, disguised knives and bayonets are all offensive weapons and prohibited from carriage.
Any knife with one of the following characteristics is an offensive weapon and prohibited:
Any item (e.g. comb) designed to look like a knife or other weapon will be seized as an imitation.
It is a criminal offence to carry some kinds of weapons at airports.
Possession of these knives at an airport is an offence punishable by a term of imprisonment and may result in:
You will be asked to relinquish all dangerous or prohibited items found in your carry-on luggage. If you refuse:
We x-ray bags going on planes to make sure there is nothing dangerous in them. If something comes up on the x-ray that needs checking, the bag will be opened, searched and any dangerous or prohibited item will be removed.