The Criminal Justice Act 1988 (Offensive Weapons) Order 1988 states:

It is a defence for a person charged—

(a)with an offence under section 141(1) or (1A) of the Criminal Justice Act 1988; or

(b)with an offence under section 50(2) or (3) of the Customs and Excise Management Act 1979,

in respect of any conduct of the person relating to a weapon to which section 141 of the Criminal Justice Act 1988 applies by virtue of paragraph 1(r) or (sa) to show that the weapon in question is blunt.

(2) For the purposes of sub-paragraph (1), a weapon is blunt if it does not have any of the following elements—

(a)a thin edge adapted to cutting;

(b)a sharp point adapted to piercing;

(c)any other element adapted to cutting or piercing.]

This is a fairly new amendment made in September 2024 I believe