I have never had much time for Rod Liddle's opinions and, having read the linked article, that is unlikely to change, though I accept that Brighton & Hove Council asking parents of a four year old what gender their child self-defines as seems a bit over-the-top.
On that point, I agree with Luckygirl that young children should not be given hormonal treatment until they have had several years to be sure that they are in "the wrong body". Added to that, boys should not be frowned upon for preferring to engage in activities that traditionalists see as "feminine". The same applies to girls but I think it is far more socially acceptable for a girl to be called "a tomboy" than it is for a boy to be called "a cissy". If gender roles are so rigidly applied (and they still are - as seen with boys and girls toys, clothes, etc.) some children will increasingly feel that they cannot be a boy/girl if they identify more with what are supposedly more masculine or feminine behaviours and activities.