A former employee at the pollster claimed the survey showed Jeremy Corbyn had won a TV debate during the 2017 election "by a country mile".
"It's the story about government staff parties that seems to be killing Johnson."
A YouGov poll also found 4% of people want politicians prioritised over the general public when it comes to the Covid vaccine.
Ministers told to get on top of monitoring technology as majority of workers “simply not ready” for it, YouGov polling shared with HuffPost UK suggests.
Donald Trump places 15th in the survey, trailing Bill Gates, Elon Musk, the Dalai Lama and Vladimir Putin.
The YouGov poll showed 57% of women surveyed agreed that trans people should be able to self-identify as their chosen gender.
Study based on YouGov MRP poll suggests just 21,215 voters can decide election if they vote tactically to deny the Tories in 30 seats they are currently expected to win.
YouGov's survey indicates Boris Johnson's lead has narrowed since it earlier predicted a bigger 68-seat majority.
YouGov's survey correctly forecast a hung parliament two years ago.
YouGov snap poll found public split down the middle on who should be prime minister.