The World Health Organisation define rape as 'the physically forced or otherwise coerced penetration of the vulva or anus with a penis, other body part or object'.
The UK Law seems to place more emphasis on consent rather than force, which is great, but states that someone can only be raped by a penis:
1-(1) A person (A) commits an offence if—
(a) he intentionally penetrates the vagina, anus or mouth of another person (B) with his penis,
(b) B does not consent to the penetration, and
(c) A does not reasonably believe that B consents.
(2) Whether a belief is reasonable is to be determined having regard to all the circumstances, including any steps A has taken to ascertain whether B consents.
(3) Sections 75 and 76 apply to an offence under this section.
(4) A person guilty of an offence under this section is liable, on conviction on indictment, to imprisonment for life.
Interested as to why the UK law seems to be at odds with the WHO definition and other countries such as the US? And possibly many others. Would a combination of the two definitions be more appropriate? Wondering if I am the only one who thinks the UK definition seems rather narrow in comparison?