A man who narrowly survived an ebike battery fire that killed his partner and two children says he is tormented by grief and guilt but determined to fight to change the law to avoid similar tragedies.

Scott Peden, 31, was placed in an induced coma for a month after suffering 15% internal burns when he tried to wrestle his burning ebike out of his Cambridge flat last June. He also smashed his heel in three places jumping from his bedroom after the battery exploded.

When he was pushed back by the flames and toxic fumes he called to his partner, Gemma, 31, and children, Lilly, eight, and Oliver, four, to jump from the same bedroom. “She said: ‘I can’t get out.’ That’s the last words I heard. I don’t know what happened,” Peden said.

He added: “Gemma knew I tried to help, but did the kids? Was their last thought ‘where’s Dad?’ I feel so much guilt and fear about what they went through in those last couple of minutes, it hits me every day.”

Peden learned of their fate only when he emerged from the coma in a burns unit in Broomfield hospital in Chelmsford. He says: “They told me Oliver was found in his bedroom. Gemma was found in our bedroom doorway and Lilly was under our beds with the two dogs.” The fire destroyed the family’s council flat and everything in it.

Cambridgeshire police told Peden that his family and the dogs all died from lithium gas poisoning. An inquest into their deaths will take place after police have concluded an investigation. It has so far focused on the previous owners of a secondhand battery that Peden bought online days before it exploded in his hallway.

Gemma, Oliver and Lilly were among 11 people killed in fires caused by ebike batteries in the UK last year, believed to be the highest number in a single year. Coroners, fire officers and campaigners have expressed growing alarm about rising sales of unregulated and potentially lethal batteries.

The number of fires from ebikes and escooters in London more than doubled in two years, from 78 in 2021 to 179 last year, according to figures from the London fire brigade. In the first five months of this year there have already been 66 such fires in the capital.

Peden is backing a campaign by the charity Electrical Safety First (ESF) for a law change to ensure there is independent third-party certification in the sale of such batteries, as there is with other dangerous products such as fireworks.

Speaking from the Cambridge flat where he has been rehoused, Peden said he was an “unlikely poster boy” for the campaign as he was dealing with his own trauma. He said: “I used to dream the whole experience over and over again. The PTSD means that sudden bangs put me in a panic attack.”

But, he added: “Campaigning has given me a sense of purpose. My life has been ruined but I can help save someone else’s.”

At the time of the fire, Peden was working for M&S unloading early-morning delivery trucks. He shared the ebike with a colleague who worked the evening shift. When the battery was stolen he could not afford the £600 it cost for a new one.

After having struggled financially, the family was looking forward to Oliver starting school as Gemma could get a part-time job. He said: “Our lives were just beginning. We were looking forward to finally taking the kids on holiday. And it all got snuffed out in a night.”

Peden has not spoken to Gemma’s family since the funeral and says they are unlikely ever to forgive him. Asked what he would say to them, he said: “I’m sorry, that’s all I can say. Should I have just used a push bike? It’s all my decisions that I have to live with.”

It was not Peden’s fault that the battery was unsafe or that it was so easy to buy online. Picking up his phone, he showed that within seconds he was being targeted with adverts on social media for similar secondhand batteries with no safety warnings or certification.

The Department of Business and Trade said a Whitehall taskforce had been set up to tackle the problem and research had been commissioned to understand the cause of fires in lithium batteries.

Peden is frustrated by the delays. “The longer they take to regulate, the more the bodies will pile up,” he said. He urged the next government to introduce ebike safety laws as soon as it came into office. “If my story doesn’t show the desperate need for a change in the regulation, then I don’t know what will.”

In a campaign video for Electrical Safety First, he said: “We are trusting the government that they are safe, but they are not. They need to be regulated, they need to be checked. Change the rules to save someone’s life.”

Lesley Rudd, ESF’s chief executive, said: “Across the country people are dying because of these fires, and people like Scott are left living with the grief and devastation. The status quo is killing people and ruining lives.”