In February 2018, Wallace was criticised by political opponents for promoting unfounded smears on the leader of the Labour Party. "The Sun" newspaper had alleged that during the 1980s Jeremy Corbyn had colluded with a Communist spy. In response to the allegations, a spokesman for Corbyn stated that any suggestion that the Labour leader had been an agent, asset or informer was "an entirely false and a ridiculous smear". Amidst these allegations, Wallace was criticised for tweeting: "'Jeremy has been interested in foreign policy issues his entire political career' – Labour MP Louise Haigh, BBC Daily Politics – yup so was Kim Philby". Wallace later defended his tweet, and said he "wasn't comparing, just saying that being interested in foreign policy isn't an answer to the allegations being made". Wallace told Sky News: "It was a light-hearted dig at Louise Haigh's excuse that Corbyn was interested in foreign affairs ... I was simply saying Kim Philby was also interested in foreign affairs".