Politician Alister Jack has been forced to self-isolate as a precaution after it emerged he had coronavirus symptoms.The Dumfries and Galloway MP, who is also Scottish Secretary to the UK Government, is the third member of premier Boris Johnson’s cabinet to be affected.Mr Jack has developed “mild” symptoms, including a cough and a temperature, but had not been tested for the virus, Covid-19.He said in a statement at the weekend: “In the past 24 hours, I have developed mild symptoms associated with coronavirus.“In line with medical guidance, I am self-isolating and working from home.”Prime Minister Boris Johnson and Health Secretary Matt Hancock are both said to be experiencing symptoms.The pair flanked Mr Jack on the front benches last