Boris Johnson: '100s' invited to Downing Street drinks in May 2020 when lockdown rules were in place.
Prime Minister Boris Johnson will face questions from other politicians on Wednesday, after the claim that as many as 100 people were invited to an event in the Downing Street garden during the first lockdown.
Boris Johnson wouldn't say if he was there or not, as he says an investigation is underway.
But why is it such a big problem for the PM? Jenny has been finding out more.