Daisy Goodwin is disappointed with ITV for using "Victoria" as a "line of sandbags" against the BBC's "Line of Duty".
The 57-year-old screenwriter is unhappy that the network didn't air her show before viewers in America were able to watch it in January, and claims the drama was used to rival the hit BBC series.
Writing in the Radio Times magazine, she said: "These Machiavellian types don't care about the patriotic right of British Victoria fans to see their heroine first.
"It's a dark art, scheduling, and it can be very demoralising for people who have dedicated themselves to making something special to realise that, for the scheduler, your carefully honed drama is nothing more than a line of sandbags against "Bodyguard 2" or, in Victoria's case, "Line of Duty"."
Daisy thinks a number of UK fans may have already watched "Victoria" "in ways that are possibly illegal but easy to master".
The show - which covers the early life of Queen Victoria - first aired in 2016 and stars Jenna Coleman as a young Queen Victoria and Tom Hughes as Prince Albert.
And Daisy is hoping next year's series will be moved in line with the US broadcast.
She said: "The next series of "Victoria" will be the darkest yet.
"I hope that the gods of scheduling look favourably upon it and decide to put it out simultaneously with the US broadcast."