Even after a decade’s experience as a doctor in conflict and disaster zones, Rosena Allin-Khan was appalled at the sight of sick and dying children separated from their parents when she visited hospitals in Jerusalem and the West Bank earlier this year.

“I saw wards full of children with the saddest eyes I’ve ever seen,” the Labour MP told the Observer. “I met children undergoing chemotherapy without their parents to support them. In a neonatal unit I saw a baby, the only survivor of premature triplets, whose siblings had died without their mother being able to hold them. I thought, this is wrong; it’s inhumane.”

She had gone to Israel not as a politician but “with my doctor’s hat on”, to investigate the availability of healthcare for Palestinians, particularly those living in Gaza, from where travel is strictly controlled by the Israeli government.

When she returned to the UK, she decided to use her weight as an MP to pursue the issue. She wrote to Jeremy Hunt, then foreign secretary, urging the government to “lean on Israeli authorities to overhaul this inhumane system of deterrence and restricted access to healthcare”.

She went on the Today programme to talk about the difficulties faced by parents of sick children in Gaza in getting permits to travel to visit them in East Jerusalem and the West Bank. Israel’s deputy ambassador to the UK, Sharon Bar-Li, also appeared on the programme. She invited Allin-Khan to continue their discussion at a meeting at the embassy.

Rosena Allin-Khan with a young patient at a hospital on the West Bank.

After that meeting Allin-Khan tweeted: “It was a pleasure to meet @SharonBarli again at the Israeli Embassy to continue our constructive discussions about access to healthcare for Palestinians. I look forward to continuing to work together on such crucial humanitarian issues.”

And that’s when it all kicked off.

“The pushback was just horrific, unlike anything I have ever experienced,” said Allin-Khan. “I didn’t anticipate a backlash of this nature at all. I was genuinely astonished, and deeply disappointed, at this unleashing of antisemitic abuse on Twitter.” The tweets included accusations that she was a “direct collaborator in apartheid” for having held talks with Israeli diplomats, and of having been “bought by the Zionists for a bag of silver and a duplex in Marbella”. One said: “Disgusting. Collaboration with occupiers and oppressors. Shameless.”

Allin-Khan responded with a Twitter thread on antisemitism, explaining the background to her meeting. She wrote: “Instead of supporting my work, those purporting to support the Palestinian cause have spouted horrible antisemitic abuse … these views are abhorrent – but also misguided and ill-informed.

“This behaviour does nothing to help the Palestinian cause. I have been there, called out what I’ve seen and spoken in the press. Am I now not meant to work to improve this dreadful situation?

I have criticised human rights abuses in Bahrain, but that doesn’t make me Islamophobic

“I have worked with Palestinians across the Middle East for 10 years – but these racists think they can sit behind a keyboard in the UK and troll someone who is genuinely trying to help. It’s revolting – it’s wrong.”

The abuse directed at her included “basic antisemitic tropes” and “further backlash from people unable even to recognise antisemitism in the tweets,” she told the Observer.

Her discussion with Bar-Li had been lengthy, robust and useful. “Bar-Li agreed with me that a child dying alone is inhumane. But it’s what they choose to do about that that’s important.” The meeting had been “most definitely worthwhile”.

Dialogue and pressure were essential tools in trying to effect change, she said. “I’m not afraid of a trip to the [Israeli] embassy. But a lot of people might be put off by the levels of abuse and be discouraged from speaking out.”

The Twitter trolls who purport to be championing the Palestinian cause were not interested in negotiation and dialogue, she said. “In a battle over who can shout the loudest, it’s the most vulnerable who lose out.”

Jewish “friends and comrades” in the Labour party had been supportive of her efforts to raise the issue of Palestinians’ access to healthcare.

The party’s own issues with antisemitism were ugly and depressing, she added. “There is absolutely no place for antisemitism. At the same time, there must be robust criticism of the Israeli government’s policies and actions.

“I have called out genocide against the Rohingya in Myanmar, but that doesn’t mean I have anything against Buddhists,” she said. “And I have criticised human rights abuses in Bahrain, but that doesn’t make me Islamophobic.”

Allin-Khan has been the MP for Tooting, south-west London, since a byelection in 2016 after the previous incumbent, Sadiq Khan, became mayor of London. Her mother is Polish, her father originally from Pakistan, and she is Muslim. She spent more than 10 years working as a humanitarian doctor in the Middle East, Africa and Asia, and she still does occasional shifts in the A&E department of her local hospital, St George’s in Tooting.

According to pressure group Physicians for Human Rights-Israel, more than 7,000 travel permits were issued to children from Gaza last year, but fewer than 2,000 were issued for parents to accompany them. The Makassed hospital in East Jerusalem has said that, in the 18 months to June this year, six babies died there without a parent present.

After three conflicts in the past 12 years, hospitals in Gaza excel at treating trauma injuries. But they often lack the drugs and equipment needed to treat cancer and other serious diseases.

Despite the onslaught against her on Twitter – which Allin-Khan described as cowardly – the MP said she would redouble her efforts to persuade the Israeli government to ease travel restrictions for the parents of sick Palestinian children. “This inhumanity has to stop.”