Hillary Clinton has condemned the BDS movement in a letter to longtime supporter and Hollywood mogul Haim Saban and dozens of other Jewish leaders.

Clinton, the frontrunner in the race for the Democratic party presidential nomination, wrote to Saban to ask for his advice on “how leaders and communities across America can work together to counter BDS”. She expressed the opinion that BDS “seeks to punish Israel and dictate how Israelis and Palestinians should resolve the core issues of their conflict”.

The Boycott, Divest and Sanction (BDS) movement, spearheaded by Palestinian advocacy groups who claim Israel is similar to apartheid South Africa, seeks to boycott companies which do business in the State of Israel and encourages organizations and institutions to divest from the country until Israel ends what they call “its occupation and colonization of all Arab lands”.

In the letter dated 2 July, Clinton said “the BDS campaign is counterproductive to the pursuit of peace and harmful to Israelis and Palestinians alike” and pledged to mount a bipartisan effort “to fight back against further attempts to isolate and delegitimize Israel”.

Aaron Keyak, a prominent pro-Israel Democrat, met Clinton’s letter with praise. Keyak said “the BDS movement is not just anti-settlement or anti-Israel, it is fundamentally founded on antisemitic ideology. Reasonable people can talk about what the best way to bring about a two-state solution but there will be no peace so long as the other side doesn’t recognize Israel’s fundamental right to exist.”

He went on to say that this is just a reminder that Clinton “is not only pro-Israel but a strong pro-Israel leader” and expressed the hope that this letter “will prevent the sort of hyperbolic over-the-top attacks from Republicans saying that she is somehow anti-Israel”.

But Yousef Munayyer, a Palestinian-American scholar and director of the US Campaign to End the Israeli Occupation, told the Guardian: “Hillary Clinton demonstrated once again that she is a creature of Washington that is out of touch with the progressive base of her party.”

Munayyer added: “At a special moment in this country, when progressive dynamism is leading the charge on equality and social justice, Clinton chose to side with the forces who support inequality and injustice for Palestinians. Her stance on BDS might win her some campaign contributions but it will do little to convince anyone she represents positive change.”

On the right, Noah Pollak, the executive director of the Emergency Committee for Israel, said Clinton’s letter was “welcome news” but was still skeptical of her bona fides on the issue. He went on to warn “she will not be taken seriously as a pro-Israel candidate if she comes out in support of Obama’s Iran deal”.

Clinton’s letter represents one of her most detailed statements on any issue related to foreign policy since announcing her plans to run for president in April.