Two British men killed while fighting Islamic State in Syria are expected to be repatriated on Tuesday afternoon.
Sniper Jac Holmes, from Bournemouth, had been battling against the extremist group with the Kurdistan People's Protection Units (YPG) since January 2015.
The 24-year-old, who had no previous military experience, was killed as he was clearing mines in the newly liberated city of Raqqa in October.
Ollie Hall, also 24, from the Portsmouth area, had only been in the war-torn country for about four months when he died in November.
His mother, Jane Lyndon, told The News in Portsmouth that he had not been been killed while clearing mines, as was previously reported, but was instead checking to see if the home of a refugee and his infant daughter was safe from bombs.
She told the newspaper: "I have been told that Ollie undoubtedly saved three families' lives and the rest of his colleagues that were there that day.
"His actions over the months he worked there would have saved many more lives due to his bravery.
"He risked his life and his freedom, put himself in harm's way to help strangers.
"His commander expressed that he was liked by everyone and a tragic loss for all that knew him."
Ms Lyndon said her son was killed while serving with the YPG, adding that, without his family's knowledge, he travelled to Syria on August 18 and spent five weeks in an academy in Rojava, in the north of the country.
The bodies of Mr Holmes and Mr Hall are expected to be arrive at Heathrow Airport on Tuesday afternoon.
Mark Campbell, co-chairman of the Kurdish Solidarity Campaign, wrote on Facebook on Monday: "Jack and Ollie are coming home. They gave their lives to fight with the Kurdish forces against Isis. Let's honour them and their families by marking their return tomorrow at Heathrow and paying our respects. Bring flowers."
He wrote that the repatriation is expected to take place at 3pm, adding: "Join us to welcome and honour our heroes returning home. Our heroes, UK volunteers Jac Holmes and Oliver Hall, joined YPG to fight the barbaric Isis and fought heroically for humanity, love and peace and (were) martyred in Raqqa while rescuing civilians and families."
Mr Holmes' mother, Angie Blannin, previously told the Press Association: "He stood up for what he believed in and he had the courage of his convictions to go out and do something where he thought that the West were not doing enough."
The other British fatalities fighting against IS are Mehmet Aksoy, 32, Luke Rutter, 22, Ryan Lock, 20, Dean Evans, 22, and Konstandinos Erik Scurfield, 25.
Raqqa had served as the capital of IS's so-called caliphate since 2014, and had been under the group's control for more than three-and-a-half years until its liberation in October.
The YPG is mostly made up of Kurdish men and women fighting against IS in northern Syria.