Unfortunately, this is a truth which has evaded several Labour figures recently, with Jeremy Corbyn becoming the latest to fall victim to the epidemic of numerical amnesia.
The party leader decided to follow up a fairly successful performance in Monday night’s Channel 4/Sky Q&A with an interview with Radio 4’s Woman’s Hour. The aim of the appearance was to promote Labour’s new childcare policy, which would see the current provision of 30 hours of free care extended to all two to four-year-olds.
However, when faced with the crucial question about costings, Mr Corbyn drew a spectacular blank. In an excruciating exchange, the Labour leader first offered up an estimate of “a lot”, before asking interviewer Emma Barnett if she could “come back to that in a moment”. He was then reprimanded live on air for trying to look up the figures on his I-pad, before an exasperated Ms Barnett provided the answer for him.
If this was a one-off, it would almost be forgivable. We’re in the midst of an intense election campaign, and Mr Corbyn was speaking after a late-night debate. But coming off the back of Diane Abbott’s policing blunder and Angela Rayner’s equally shambolic class-size interview, it reeked of unprofessionalism and only works to reenforce the Tory message that Labour are weak on the economy.
Fortunately Mr Corbyn had the correct numbers to hand later in the day when he joined users on Mumsnet for a live Q&A. The webchat saw the Labour leader quizzed about his previous responses to the Mumsnet “biscuit test” in which he revealed he was “anti-sugar” but would eat a shortbread “if forced”. In a bid to avoid a repeat of biscuit-gate, he was keen to play-up his jam making credentials, focussing instead on sugar in ”moderation”.