British Prime Minister David Cameron on Thursday expressed concern after 41-year-old British MP from the opposition Labour Party Jo Cox was shot and stabbed in her constituency in northern England. She is said to be in a critical condition. In a series of tweets, Cameron said he was concerned about reports of her injury. The British PM was scheduled to make a two-hour visit to Gibraltar Thursday to seek votes to keep Britain in the EU in the June 23 referendum. But he wrote on Twitter "I won't go ahead with tonight's rally in Gibraltar." Very concerned about reports Jo Cox has been injured. Our thoughts and prayers are with Jo and her family. — David Cameron (@David_Cameron) June 16, 2016 It's right that all campaigning has been stopped after the terrible attack on Jo Cox. I won't go ahead with tonight's rally in Gibraltar. — David Cameron (@David_Cameron) June 16, 2016 Jo Cox, a mother of two, was left bleeding on the pavement after the incident in Birstall in West Yorkshire, media reports said. READ: Labour MP Jo Cox shot, stabbed in Birstall Cox reportedly got involved in a scuffle between two men in the village of Birstall. An eyewitness said one of the men was fighting with Cox and then a gun went off twice. Very concerned about reports Jo Cox has been injured. Our thoughts and prayers are with Jo and her family. It's right that all campaigning has been stopped after the terrible attack on Jo Cox. I won't go ahead with tonight's rally in Gibraltar.