Colleagues of a doctor who works in West Yorkshire and was refused permission to leave Gaza have appealed for his safe return.
Ahmed Sabra, a consultant cardiologist at Pinderfields Hospital in Wakefield, was visiting relatives when the war with Israel began.
However, at the Rafah border he was told he could not enter Egypt.
Hospital colleagues said they want "everything possible to be done" to return him to the UK.
Dr Sabra, who is also an NHS consultant in Swansea, had been waiting to leave Gaza for a month.
However, his name was not on an approved list of foreign nationals allowed to leave, forcing him to be separated from his wife and three children, who escaped to Egypt.
He told the BBC he is happy that his family are safe, but claimed the UK government had "not done enough" to help him and has pleaded with them to help him leave.
"I'm calling on the Foreign Office to do their duty for a British national, to evacuate me and get me out of Gaza," he said.
A group of consultant cardiologists who work with Dr Sabra at Pinderfields have called for his return to the UK and described him as "a valued member of our team, providing acute cardiac care for patients in West Yorkshire".
"We are extremely concerned for his welfare," they said.
The group from the Mid Yorkshire Teaching NHS Trust said: "We have been in regular contact with him and it is clear he and his family have experienced unthinkable trauma and suffering, including losing family and friends.
"As he is a British national, we expected his safe passage across the border and we were thrilled to hear that he and his family had made it through the Rafah crossing into Egypt.
"To then find out he has been sent back to Gaza was devastating to his colleagues, friends and patients here."
'Death every day'
Dr Sabra's colleagues said they believed the Foreign Office was aware of his plight.
"We have no political axe to grind, we just want everything possible to be done as quickly as possible to get our dear friend and colleague home safe," they said.
Dr Sabra told the BBC: "We are now being sent to a death sentence.
"We're seeing death every day, we smell death, the sound of death and we felt like we died one hundred times."
A Foreign Office spokesman said: "We're working round the clock to ensure all British nationals in Gaza who want to leave are able to.
"This involves submitting all details of British nationals and eligible dependants to the Israeli and Egyptian authorities. The authorities then review all cases and give permissions to cross.
"We remain in regular contact with British nationals in Gaza to provide them with the latest information, and UK teams are forward deployed to the border to receive anyone leaving".