Julie Hesmondhalgh has urged the public not to let the momentum for change sparked by ITV's Mr Bates vs The Post Office dwindle after the drama's release.
Mr Bates vs The Post Office brought to life the Horizon scandal which has plagued hundreds of subpostmasters for decades.
The series told the story of how the Post Office accused approximately 3,500 operators of theft, fraud and false accounting based on information from the Horizon IT system it rolled out in the late 1990s.
More than 700 were prosecuted while others were vilified by their communities and some even took their own lives - despite the Post Office being aware from 2010 that there were faults in the software.
With a public inquiry still ongoing, the show has sent shockwaves through the political sphere as members of the public have demanded justice.
The impact had led Prime Minister Rishi Sunak to describe the scandal as an "appalling miscarriage of justice" and insist the government is reviewing options - including stripping the Post Office of its role in the appeal process.
Julia Hesmondhalgh has spoken out about the impact of the show
BBC
Elsewhere, more than a million members of the public have signed a petition demanding the former Post Office CEO Paula Vennells - played by Lia Williams in the drama - be stripped of her CBE.
And Sir Keir Starmer, who was Director of Public Prosecutions, has faced questions over why he failed to intervene in the scandal while Lib Dem's Ed Davey has also accused the Post Office of a "conspiracy of lies" after he served as postal affairs minister between 2010 and 2012.
The impact of the Toby Jones-led drama hasn't gone unnoticed by the subpostmasters the series portrayed as well as the actors who starred in the four-part series.
Hesmondhalgh addressed the impact head-on in a televised interview on Tuesday in which she was asked: "How does it feel to be involved in a drama which has really rocked the political establishment and has done something really important?"
"It's absolutely amazing," the former Corrie star replied. "We're all thrilled beyond anything that we can properly express.
"I think what all drama can do is cut through the facts and figures and data and what you're doing is putting real people into people's living rooms.
"You're required to put yourself into their shoes so when Lee (Castleton), played by Will (Mellor), stands in court and is told to pay the court costs, you imagine what that must be like to be in that position... you feel what that must be like and it gives you empathy, that's what drama can do.
"I've seen it happen so many times from my years in a continuing drama... I think that it can really cut past that and especially something like this which spans so many years.
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Toby Jones leads Mr Bates vs The Post Office in the titular role
ITV/SHUTTERSTOCK
"It's very difficult - people knew little bits from the story over the years but it's been hard to keep any momentum going.
"There have been some really amazing people trying to keep it going for years... but it's never quite grabbed the public imagination in the way that it has now."
Pleading for the public to continue asking for justice, Hesmondhalgh concluded: "So we've got to grab this momentum and keep rolling with it.
"It's big news this week but we've got to make sure it stays in people's hearts and minds for weeks that follow."
