YouTube has been criticised by broadcasters and advertisers after withdrawing from the UK’s main television audience measurement system, just months after agreeing to be measured alongside traditional TV channels and rival streaming platforms. “If they want to be treated like TV, they need to be transparent.”YouTube is estimated to generate almost $2bn (£1.5bn) a year in UK advertising revenue, according to eMarketer. Its participation in Barb’s measurement system was announced last February as part of a broader push by digital platforms to attract larger TV advertising budgets by allowing cross-platform comparisons. Figures for December showed YouTube overtook the BBC’s combined channels for the first time in terms of UK viewing across TVs, smartphones and tablets. Last year, YouTube said TV sets had overtaken mobile devices as the primary way its content is watched in the US.