Palestinian-American lawmaker Rashida Tlaib on Friday turned down Israel's offer to let her visit her grandmother in the occupied West Bank, owing to restrictions she termed oppressive.
It was the latest twist in a saga hinging on Israel's war against those who would boycott it over its treatment of the Palestinians.
On Thursday, Israel barred from entry the US Congress' first Muslim women lawmakers, Tlaib and Ilhan Omar, on the grounds that they support the boycott movement, and after President Donald Trump urged the Jewish state to block the two Democrats.
But it held out the carrot of allowing Tlaib to make a private visit to her elderly grandmother, if she agreed to abide by conditions including a pledge not to advocate boycotting Israel.
"This could be my last opportunity to see her. I will respect any restrictions and will not promote boycotts against Israel during my visit," she intially wrote.
On Friday, Israel's Interior Minister Aryeh Deri announced that she would be permitted a "humanitarian visit", but a few hours later Tlaib announced a change of heart.
"I have decided that visiting my grandmother under these oppressive conditions stands against everything I believe in - fighting against racism, oppression & injustice," she wrote in a series of tweets.
"When I won, it gave the Palestinian people hope that someone will finally speak the truth about the inhumane conditions," added the 43-year-old freshman congresswoman, elected in January.
"I can't allow the State of Israel to take away that light by humiliating me & use my love for my sity to bow down to their oppressive & racist policies," she said, referring to her grandmother.
"Silencing me & treating me like a criminal is not what she wants for me. It would kill a piece of me."
On Friday, Palestinian activists had been urging Tlaib on social media not to visit her grandmother under the Israeli terms.
In the family's village of Beit Ur Al-Foqa, Muftia Tlaib had been excitedly awaiting her granddaughter's arrival.
She intended to slaughter a sheep in her honour, in accordance with custom.
"I see her coming to the village in traditional (Palestinian) dress," she told AFP on Thursday, before the latest development.