Scottish Conservatives virtual conference to attack the SNP and a second independence referendum.During his 10-minute speech the Prime Minister said Nicola Sturgeon's party is "not invincible".The Prime Minister set a task for Scottish Tories to stop an SNP majority at May's Holyrood elections and blunt nationalist demands for a second independence poll.Speaking online to the virtual spring conference, the PM did not definitely rule out a second referendum, although he has in the past said he