The producer is said to have made a list of characters he thinks are "urgently in need of attention" to avoid viewers forgetting about them.
Newcomer Stella Price (Michelle Collins), husband Karl (John Michie) and their daughter Eva (Catherine Tyldesley) are top of the list. They need a big storyline so that they're "accepted" by the audience, The People reports.
Chesney Battersby-Brown (Sam Aston) and his pregnant girlfriend Katy Armstrong (Georgia May Foote) were also highlighted as being in need of attention. Collinson apparently insisted that the pair can't simply disappear until Katy's baby is due around Christmas time.
Gail McIntyre (Helen Worth) and son Nick Tilsley (Ben Price) - who beds Becky McDonald (Katherine Kelly) later this year - will get new storylines. "Nick is a character that definitely needs work. We need a big story for him that will take him in a different direction," Collinson told scriptwriters.
"Previous ideas put forward for the character are not really appropriate. And where are we going with Gail? Does anyone have a story idea that will see her take centre stage?"
Meanwhile, Sean Tully (Antony Cotton) and Marcus Dent (Charlie Condou) will see their relationship under threat in the coming months when Dylan returns home to mum Violet Wilson.
Collinson also requested "fresh" plots for Norris Cole (Malcolm Hebden), Mary Taylor (Patti Clare), and Roy (David Neilson) and Hayley Cropper (Julie Hesmondhalgh).
The producer also suggested a change in direction for Gary Windass (Mikey North) and girlfriend Izzy Armstrong (Cherylee Houston), who is mugged in the coming weeks.
"Collinson really didn't pull any punches," a source said. "The team of scriptwriters was told in no uncertain terms that they needed to do much more."
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