All railway lines are blocked between Carlisle and Lockerbie due to a fallen tree.
The tree hit overhead power equipment at Floriston near Gretna.
Network Rail, which manages Britain's rail infrastructure, is attempting to repair the damage.
Virgin Trains said it is not possible for passengers to use the East Coast Main Line as an alternative route due to disruption caused by a person being hit by a train.
A spokesman for the operator said: "The closure of our route to Scotland is causing significant disruption and we want to apologise to all our customers affected by this.
"We're doing our best to help people complete their journeys but would advise anyone who has not set off on their journey to either wait until the disruption has cleared, travel tomorrow or get a refund."