Casino tycoon Sheldon Adelson, a major contributor to Mitt Romney’s election effort, is pressing the Republican nominee to come out for the release of Israeli spy Jonathan Pollard, a major Republican donor and associates of Adelson and Romney tell The Daily Beast.

Romney has rejected the request so far, telling Adelson he would have to review the relevant intelligence material accessible to him as president before granting Pollard clemency, said the sources, who are relaying accounts of conversations from both Adelson and Romney. Romney “could not consider the Pollard situation because he doesn’t have access to the classified information,” one source said.

The issue is apparently one of a handful where Romney differs from Adelson on Israel. The billionaire has also asked Romney to state publicly that Israeli-Palestinian peace talks are a waste of time because the Palestinians are unwilling to make peace, according to the sources—and he wants a firmer commitment from Romney to move the U.S. Embassy in Israel from Tel Aviv to Jerusalem, in what would be a de facto recognition of Israel’s annexation of East Jerusalem. For his part, Romney has not said peace talks are a waste of time and has gone only partway on the embassy question, saying he would undertake the move in consultation with the Israeli government—a campaign promise other presidents have made. (Adelson has pressed Romney to pledge to move the embassy without consulting the Israeli government.)

Spokespeople for both men declined to comment on the private talks between Adelson and Romney. Ron Resse, a spokesman for Adelson, was willing to say that the two men were not always on the same page. “People that support candidates are bound to disagree with these candidates on some particular issues,” he told The Daily Beast. But he said Adelson and Romney agree “on most big issues.” Asked what Adelson expected from Romney in return for his support, Reese said the billionaire has no expectations in terms of foreign or domestic policy. “He hopes to be invited to the Chanukah party at the White House,” Reese said.

Adelson himself has acknowledged that he has a channel to Romney. “I have talked to Romney many, many, many times,” Adelson told The Jewish Journal in March, when he was still supporting the failed candidacy of former House speaker Newt Gingrich. “As recently as when he was here in Vegas for the caucuses. He’s not the bold decision maker like Newt Gingrich is. Every time I talk to him, [he says] ‘Well, let me think about it.’ Everything I’ve said to Mitt, he’s said, ‘Let me look into it.’ So he’s like Obama. When Obama was in the Illinois Senate, 186 times he voted present. Because he didn’t want to damage his record.”

Despite these disparaging remarks, Adelson assured the former Massachusetts governor during the primaries that he would have his support if he became the nominee, according to Romney donors and an associate of Adelson’s. And, in recent months, the two have indeed found common cause in the quest to oust Obama from the White House. Adelson has said he would give up to $100 million in this election cycle to defeat President Obama, and he recently accompanied Romney on his tour of Israel at the end of July. At a fundraiser at Jerusalem’s King David Hotel, he even introduced the candidate to the 50 or so donors in the room, according to two people present. (Participants paid between $25,000 and $50,000 to hear Romney speak.)

Yet the two appear to have a significant difference on Pollard. A former naval intelligence officer, Pollard was sentenced to life in prison in 1987 for selling U.S. secrets to Israel—a crime that he acknowledged committing at the time, and which the Israeli government itself formally acknowledged in 1998. In recent years, a string of former and current national-security officials and politicians have come out in favor of granting clemency to Pollard in part because he is the only spy for an allied nation to receive a life sentence. At the top of the list are James Woolsey, a former CIA director; Lawrence Korb, a former senior Pentagon official at the time of Pollard’s arrest in 1986; and Sen. John McCain.

Nonetheless, successive U.S. presidents have refused to pardon him on the recommendation of security officials and due to the severity of his espionage. Pollard stole a huge volume of documents, including some of the intelligence establishment’s most sensitive secrets. Former CIA director George Tenet wrote in his 2007 memoir that he threatened to resign his post in 1998 if President Clinton granted Benjamin Netanyahu’s request to release Pollard. (Netanyahu, now in his second stint as Israel’s prime minister, made the same request of Obama in January 2011.)

In December Romney was asked for his view of Pollard at a meeting with the Conference of Presidents of Major American Jewish Organizations. According to Malcolm Hoenlein, the group’s CEO, “He did not say what people wanted to hear. Instead he gave a more nuanced response and pointed to the fact that when he was governor of Massachusetts, he did not review decisions of the court unless there was judicial misconduct. When some in the audience raised information about the disproportionate sentence and some of the allegations of judicial misconduct in the Pollard case, Romney said he would review the facts when he was president.”