The mother of a boy who died during floods in Surrey in 2014 says she is unable to grieve until his death is examined by an independent panel.
Zane Gbangbola's parents claim hydrogen cyanide gas from a former Chertsey tip killed their seven-year-old son.
His mother Nicole Lawler said: "We do very much feel like we walk alone a lot of the time. Zane to the world is just one child but to us he was the world."
She spoke at a campaign event held by the legal group the Haldane Society.
Ms Lawler said: "We are very much stuck in this minute in time. We aren't able to grieve. We have to relive."
She described how the incident that killed Zane and left his father paralysed, left her for a time sleeping on a hospital floor.
"Porton Down had seized the house. We had nothing to hold on to of Zane's," she said.
"It's not until you've faced your greatest fears and it's not until you've lost everything that you gain an armour."
Zane's father, Kye Gbangbola, who has collated a range of information he wants examined by an independent panel, said: "All we have ever asked for is an investigation based on the true evidence."
The couple dispute an inquest which found their son died from carbon monoxide from a pump used to clear flood water, and have always said the pump was not in use.
They have been denied an independent panel inquiry by the government.
Deborah Coles, executive director of Inquest, said there were different routes to challenging an inquest including judicial review, which required legal aid, or an inquiry as was seen with Hillsborough.
She said a Hillsborough-style panel would have people with expertise in "uncovering, reviewing and bringing out the truth through the panel process".
On 21 October - Zane's birthday - parents and campaigners will deliver a 111,000-name petition to Downing Street, demanding an independent panel inquiry.
Ms Lawler said: "Zane will always be forever seven, so it's very significant we are trying to do something for Zane on his birthday."
This year, Zane would have been 16.