Zach Eagling, a schoolboy from the village of Hartshead who has epilepsy and cerebral palsy, began campaigning for the legislation after he was targeted by trolls who wanted to cause a seizure four years ago.

But this week MPs introduced ‘Zach’s Law’ as part of the Online Safety Bill, which makes it illegal to send flashing images by email or social media to someone with epilepsy when they know that person “will suffer harm as a result of viewing”.

Zach's mum, Claire Keer, said: “I could not be prouder of what Zach has achieved. For the past three and a half years, he has been spearheading the Zach’s Law campaign run by the Epilepsy Society to bring these trolls to justice.

“He has taken time out of school to meet with politicians, policy makers and the media. He has taken on the internet trolls and won."

Kim Leadbeater, the MP for Batley and Spen who has been supporting the campaign, said Zach is “a force to be reckoned with”.

“For many years, vile online trolls have targeted people with epilepsy, sending them flashing images and GIFs, trying to trigger a seizure. Zach stood up against this,” said the Labour MP.

“When he asked me to help, along with Claire and the Epilepsy Society, I was only too happy to do everything I could. It’s been a long and difficult campaign, with the Online Safety Bill delayed by ministers again and again, but we have finally got there.”

The Epilepsy Society said it has also been targeted by internet trolls sending flashing images.

Chief Executive Clare Pelham said “Three years ago, when the Epilepsy Society’s Twitter account was flooded with flashing images and GIFs designed to cause seizures, we felt helpless in trying to stop them.

“The trolls were operating beyond the reach of the law because the law, written in the time of typewriters and printer’s ink, had not kept pace with the digital world.”

The Online Safety BIll, which has been years in the drafting, imposes new legal duties on big tech companies and service providers, overseen by the regulator Ofcom.

The reforms come in response to continuing concern about youngsters accessing pornographic content online, child sexual abuse in cyberspace and the impact of harmful material on social media, which has led young people to take their lives.

The legislation aims to make social media platforms responsible for the content they host.

If they do not act to prevent and remove illegal content they will face significant fines of up to £18m or 10 per cent of global revenue – potentially billions of pounds – and in extreme cases their bosses could even face prison.

Yorkshire schoolboy, 12, convinces MPs to introduce new law targeting malicious trolls