[randomcarbloke]

in america yes that is a good rule of thumb

>said the UK should require importers to label the country of origin on all honey, including blends

It actually does require that, it must specify country of origin and whether it is a blend, if it's a blend then it contains syrup and possibly antibiotics.

Buy single origin which in europe is certainly available, in the UK avoid anything that has the line "a blend of EU and non-EU honey", you should be buying UK honey anyway if you're UK-based, it is better and not blended (except where fraud has been committed as in the article).