You shouldn't jut take the guardian's word for it (atually the observer, who hate corbyn even more). The latest opinium for the observer has a 12 point lead, but that poll always roasts labour, almost as bad as yougov. Another poll released today (comres/sunday express) gives the tories a 1 point lead. It's probably still bad for labour on average, but not quite as bad when you drop the outliers.