Was or is possession of screwdriver illegal in the UK?
Yes, if the screwdriver's intended purpose is for a criminal act.
There's not enough detail in the article, but the most likely scenarios are:
- Offensive Weapon, contrary to section 1 Prevention of Crime Act 1953:
(1)Any person who without lawful authority or reasonable excuse, the proof whereof shall lie on him, has with him in any public place any offensive weapon shall be guilty of an offence ...
[...]
(4)In this section “ public place ” includes any highway, or in Scotland any road within the meaning of the Roads (Scotland) Act 1984 and any other premises or place to which at the material time the public have or are permitted to have access, whether on payment or otherwise; and "offensive weapon” means any article made or adapted for use for causing injury to the person, or intended by the person having it with him for such use by him or by some other person.
- Going Equipped to steal, contrary to section 25 Theft Act 1968:
(1)A person shall be guilty of an offence if, when not at his place of abode, he has with him any article for use in the course of or in connection with any burglary or theft.
(2)A person guilty of an offence under this section shall on conviction on indictment be liable to imprisonment for a term not exceeding three years.
(3)Where a person is charged with an offence under this section, proof that he had with him any article made or adapted for use in committing a burglary or theft shall be evidence that he had it with him for such use.
[...]
(5)For purposes of this section an offence under section 12(1) of this Act of taking a conveyance shall be treated as theft.
- Possession with intent to destroy or damage property, contrary to section 3 Criminal Damage Act 1971:
A person who has anything in his custody or under his control intending without lawful excuse to use it or cause or permit another to use it—
(a)to destroy or damage any property belonging to some other person; or
(b)to destroy or damage his own or the user’s property in a way which he knows is likely to endanger the life of some other person;
shall be guilty of an offence. [with a maximum sentence of 10 years]
NB in this jurisdiction, possession of a weapon for self-protection is not, except in some very narrow circumstances, a reasonable excuse to carrying one.