Social media users were given creative license after a trick of the light appeared to show a blank placard in the crowd during Sir Keir Starmer’s speech in Wakefield.
The Labour leader headed up to the Red Wall seat this weekend as voters prepare to go to the polls on Thursday.
Wakefield was won by the Tories in the 2019 general election after being a Labour stronghold since the 1930s.
But a by-election was called after the resignation of Conservative Imran Ahmad Khan, who won in 2019, following his conviction for sexually assaulting a boy.
The Tories have selected Wakefield councillor Nadeem Ahmed to defend the 3,358 majority the party secured in 2019.
Earlier this week, Mr Ahmed compared trust in the Tories following the resignation of Mr Khan, to faith in GPs despite the crimes of mass murderer Harold Shipman.
Labour leader Starmer has urged supporters not to be complacent with just a few days to go before the by-election, telling them a victory “could be the birthplace of the next Labour government”.
Sir Keir addressed a rally of supporters in the city centre on Saturday morning with his party now odds-on favourites to take back the seat they lost in 2019 as part of the Tories’ takeover of “red wall” constituencies across the north of England.
He said: “It feels like we can reach out and touch this. It feels positive.”
But eagle-eyed social media viewers were quick to spot a blank placard in the crowd, most likely caused by a trick of the light.
Many used the opportunity to speculate what the placard could have said, with some – seemingly convincingly – suggesting it could have contained messages of support for former Labour leader Jeremy Corbyn.
Others, meanwhile, opted for more humorous alternatives: