Israeli newspapers have bristled after the European Parliament president criticised the Gaza Strip blockade and suggested Israelis received four times more water than Palestinians.
The spat erupted on Wednesday after the far-right Jewish Home party stormed out of parliament in protest during a speech by Martin Schulz, and it made the front pages of Israel's main newspapers.
Most commentators were furious about figures mentioned by Schulz over water usage.
"How can it be that an Israeli is allowed to use 70 litres of water per day, but a Palestinian only 17," Schulz asked.
But he also admitted he had not had time to verify the numbers.
Shortly afterwards, Schulz criticised settlements as an obstacle to peace and warned that the Gaza blockade could "undermine, rather than strengthen, Israel's security".
This prompted a barrage of heckling from Jewish Home MPs, who then walked out.
Party chairman Naftali Bennett denounced both assertions as "deceitful propaganda".
Even Prime Minister Benjamin Netanyahu waded in, accusing Schulz of being quick to cast blame without checking his facts.
"What was disturbing in Schulz's speech was the selective hearing that is becoming prevalent in many circles in Europe," he said in remarks published on parliament's website.
"These are figures which are not true. (Schulz) said he didn't check the figures but it didn't stop him from straight away casting blame."
The Palestine Liberation Organisation said average daily Palestinian domestic consumption was 70 litres per person, while the World Health Organisation recommends a minimum of 100 litres.
"In the southern West Bank, there are communities that use less than 15 to 20 litres per capita per day," it added.
The spat prompted several NGOs to publish their own figures on water usage, with Friends of the Earth Middle East citing statistics from 2011 showing the ratio was close to four to one.
According to the Israeli national water company, Mekorot, the average household water consumption in Israel is between 100 and 230 litres per person per day.
For Palestinians in the West Bank connected to the water mains, the average daily consumption is about 73 litres.
