Exclusive: teaching union reveals Salford schools have test requests turned away, and 600 pupils in Bury are self-isolating
But the health secretary says he is not "putting a date" on the rollout.
A similar banner was strung up in Salford during the last Conservative conference in Manchester in 2017.
Police have arrested a man on suspicion of murder after finding a body in the woods in Salford. Hiran Chauhan, 24, was reported missing on July 4.
Early-hours incident also saw car deliberately driven towards the men.
She was reported missing last December.