A prominent actor turned Michigan politician was offered $20m to mount a primary challenge against Democratic Congresswoman Rashida Tlaib, underscoring the fierce blowback the Palestinian-American lawmaker is facing over her position on Israel.

Politico reported on Wednesday that Michigan businessman Linden Nelson made the offer to Democratic Senate candidate Hill Harper, pledging $10m in direct contributions to his potential campaign and another $10m in independent expenditures.

Harper, who left his role as a leading actor in the TV series The Good Doctor, to run for an open Michigan Senate seat, turned down the offer, according to Politico.

Nelson has a history of ties to the powerful pro-Israel lobbying group, the American Israel Public Affairs Committee (Aipac), and has contributed to previous failed campaigns to oust Tlaib from Congress.

Tlaib is an outspoken critic of Israel and has long faced challenges from Aipac. Since the outbreak of the Israel-Palestine war, she has become one of the most prominent lawmakers to call for a ceasefire. 

In a social media post, Tlaib also accused President Joe Biden, the leader of her Democratic Party, of supporting the “genocide of the Palestinian people” by providing unconditional military support to Israel. 

Earlier this month, a sizable number of Democratic members of Congress joined Republicans to censure Tlaib for her comments over the war, which critics slammed as antisemitic.

Tlaib mounted a fierce defence of her views. 

“It is important to separate people and government,” Tlaib said. “The idea that criticizing the government of Israel is antisemitic sets a very dangerous precedent. And it’s been used to silence diverse voices speaking up for human rights across our nation.”

It’s not immediately clear why Nelson pitched Harper.

The actor-turned-politician has also positioned himself as opposed to the Biden administration’s stance on the war. On 10 November he issued a statement calling for a ceasefire. Politico noted that his statement came after Nelson phoned to make him the offer.

Harper is running in a crowded field for Michigan’s open senate seat. Six Democrats and eight Republicans are running to replace Democratic Senator Debbie Stabenow, who is retiring.