Boris Johnson has hit out at the "delay" and "timidity" in helping Ukraine after travelling through the country unprotected during a 72-hour trip for a documentary.
The former prime minister travelled beyond the capital Kyiv to the so-called kill zone near the city of Zaporizhzhia where he witnessed first-hand the war between Russia and Ukraine.
The 61-year-old said Ukraine can and will win the war, but that "we are risibly failing to live up to our pledges" to the country.
Mr Johnson said: "The Ukrainians are fighting the same war against the same drones that are being sent against civilians by the same alliance of tyrannies.
"We have spent four years psalming platitudes and telling them that their fight is our fight.
"On the basis of what I have seen, we are risibly failing to live up to our pledges, and to give them the help they need.
"The Ukrainians can win and will win.
"But our delay and our timidity continue to cause unimaginable human suffering.
"We are right to say that the Ukrainians are fighting for all of us - so why the hell are we still short-changing them?"
Mr Johnson's three-day trip is the subject of a feature-length documentary film for Channel 5, produced by Soho Studios and Two Rivers Media.
Boris Johnson: Into The Kill Zone will show him alongside Ukrainian soldiers visiting locations including a secret drone base and makeshift bomb factory that is hidden inside abandoned cottages.
He will be seen sheltering in an eight-storey flat during a missile strike and joining mobile gun teams and Kyiv's volunteer air defenders for a night shift protecting the capital from Russian drone attacks.
Mr Johnson also joins the part-time soldiers of the 112th Territorial Defence Brigade to watch how mobile gun teams hunt drones in the night sky.
Speaking about the documentary film, Guy Davies, consultant editor for commissioning at 5, said: "Boris takes us on a traumatic and revelatory journey in this documentary.
"It is clearly a cause that is close to his heart and we see him in a new light - no longer looking at the war from the statesman's perspective, away from the front line, but in the trenches and more able to speak freely."
Soho Studios' founder Ian Lamarra said: "Seeing a recent British prime minister on the front line of a conflict, with his life in genuine danger, is extremely powerful.
"I think this will be the talked about doc of the year and make worldwide headlines as it sells internationally."
Mr Johnson's access to the front line was secured in collaboration with Richard Pendlebury, an award-winning foreign correspondent at the Daily Mail.
