Former Vice President and Democratic presidential nominee Kamala Harris sharply criticized senior advisers to former U.S. President Joe Biden for objecting to her tougher stance on Israel during the Gaza war, according to an excerpt from her upcoming book on her presidential campaign published Wednesday.

"Joe was already polling badly on the age issue, with roughly 75 percent of voters saying he was too old to be an effective president. Then he started taking on water for his perceived blank check to Benjamin Netanyahu in Gaza," she writes in her forthcoming book "107 Days," published in The Atlantic.

"When polls indicated that I was getting more popular, the people around him didn't like the contrast that was emerging," she adds. "In Selma, Alabama, at the commemoration of Bloody Sunday, when civil-rights marchers were attacked and beaten once they'd crossed the Edmund Pettus Bridge, I gave a strong speech on the humanitarian crisis in Gaza."

"Desperate people had been shot when they swarmed a food truck, and I spoke of families reduced to eating leaves or animal feed, women prematurely giving birth with little or no medical care, and children dying from malnutrition and dehydration," she continues. "I reiterated my strong support for Israel's security and called on Hamas to release the hostages and accept the cease-fire agreement then on the table. I also called on Israel for greater access to aid."