Other services are also affected, including the 8.25am train to Blackpool North which has been cancelled.
Northern said the disruption is likely to continue until the end of the day whilst the damaged wires are repaired at Kearsley, between Bolton and Manchester.
Some rail replacement transport will be provided, but Northern says journey times by road will be extended by 1 hour.
A National Rail spokesman said: “Damage to the overhead wires at Kearsley means all lines are blocked. As a result, Northern services between Manchester Victoria / Manchester Oxford Road and Bolton are subject to severe disruption.
"Services may be cancelled, delayed by up to 90 minutes or revised. Major disruption is expected until the end of the day.”
Blackpool North and Hazel Grove services will be diverted when able between Preston and Salford Crescent.
7.51am Preston to Manchester Oxford Road and Manchester Piccadilly
8.23am Preston to Manchester Airport
8:25am Preston to Blackpool North
8.55am Preston to Manchester Oxford Road and Manchester Piccadilly
9.25am Preston to Blackpool North
9.51am Preston to Blackpool North