A former leader of the UK Conservative Party challenged Israeli Prime Minister Benjamin Netanyahu on Thursday over the use of live ammunition against Palestinians during recent protests along the Gaza-Israel border fence.
Michael Howard, who led the Conservatives between 2003 and 2005, asked Netanyahu why Israeli forces didn't use alternatives like rubber bullets.
Netanyahu said other methods had been tried, but didn't work.
The Israeli leader was in London as part of a tour of Germany, France and the UK capitals during which he has attempted to persuade European leaders to ease their support for the Iran nuclear deal.
He faced questions on a range of issues at an event in London organized by the Policy Exchange think tank.
Howard, a prominent Jewish figure in British politics who is now a member of the House of Lords, said that many would understand the need to prevent protesters scaling the border fence during violent demonstrations. "Fewer people ... sympathize and understand the proposition that the only way to stop them scaling the fence was to kill them," he added.
"Why couldn't you use rubber bullets? Why couldn't you -- if in extremis you had to use live ammunition -- why couldn't you shoot them in the legs? Why did you have to kill them to stop them scaling the fence?"
Netanyahu responded that everything suggested by Howard had been tried, along with other methods, but that they hadn't worked. "Nobody intentionally went out to kill anyone," he said.
The Israeli leader pointed the finger at Hamas, the militant group that runs Gaza, saying it had wanted more Palestinian deaths. "Their goal was to have as many casualties. Our goal was to minimize casualties and avoid fatalities," he said.
The questions from Howard came a day after UK Prime Minister Theresa May told Netanyahu that her government was "concerned" about the loss of Palestinian lives in Gaza.
"The UK absolutely recognizes that Israel has a right for self defense," May said during an on-camera conversation in Downing Street, but added that she hoped Israel could alleviate the "deteriorating" situation in Gaza.
Responding, Netanyahu said the issue was "rooted in the fundamental goal of Hamas to destroy Israel."
"This is not a non-violent protest, quite the contrary," Netanyahu said, referring to the Palestinian Great March of Return, a series of Friday demonstrations over six weeks from March to May. More than 100 Palestinian protesters were killed by Israeli fire during the protests, according to a CNN count based on Palestinian Health Ministry figures.
Netanyahu said the Israelis were doing "everything we can" to minimize civilian casualties, "and at the same time protect Israeli lives."
Israel faced international condemnation last month after Israeli forces killed dozens of Palestinians in bloody clashes at the Gaza border as the US officially opened its Embassy in Jerusalem just 50 miles away.
The Israeli Defence Forces, or IDF, said protesters were trying to storm the border fence between Israel and Gaza. It accused Hamas of "leading a terrorist operation" and inciting the protesters to conduct what Israel described as terror attacks.
Palestinian leaders said the protests were peaceful and the use of force was wholly disproportionate to the threat.
The aim of the March of Return movement is to highlight the Palestinian right to return to homes and villages lost by their ancestors in the 1948-49 Arab-Israeli war.