The families of two scholars facing the death penalty in Saudi Arabia have appealed to the University of Cambridge to drop proposals to run staff training courses for Riyadh’s defence ministry.

The Guardian revealed last week that Cambridge’s Judge business school has been authorised to offer “leadership development” and “innovation management” training for the Saudi defence ministry’s staff, despite internal opposition within the university over the kingdom’s record on human rights and academic freedom.

The sons of the two men prosecuted for almost a decade by Saudi courts have called on Chris Smith, Cambridge’s chancellor, and Prof Deborah Prentice, its vice-chancellor, to halt any deal.

The letter says that a “prestigious partnership like this risks legitimising [the Saudi crown prince] Mohammed bin Salman’s false narrative of reform, despite evidence of continued human rights abuses. The Saudi authorities executed at least 356 people last year, the most in the kingdom’s modern history.”

Saudi Arabia’s public prosecutor is said to have called for the death penalty for the Islamic scholars and authors Hassan Farhan al-Maliki and Salman al-Odah on a “range of vaguely formulated charges”, according to international human rights organisations.

The joint letter from their respective sons Abobaker Almalki and Abdullah al-Odah says: “We feel compelled to reach out as families who have spent years watching our loved ones suffer for exercising the very freedoms that the university stands to protect.”

Al-Maliki, a religious reformer and commentator, has been imprisoned since 2017 and accused of multiple crimes including holding interviews with overseas media and possessing banned books.

In 2017, al-Odah was also arrested, on the basis of his social media posts, and accused of “mocking the government’s achievements” among other charges before the country’s secretive specialised criminal court.

Jeed Basyouni, of the Reprieve human rights organisation, said: “Universities pride themselves on being the home of free thought and academic debate. Even in the face of external pressure, freedom of speech is meant to be upheld as a foundational principle of higher education.

“Hassan and Salman risk execution because they dared to express themselves, as scholars and public figures. A deal like this makes a mockery of the values that institutors like Cambridge claim to represent, and risks further legitimising Mohammed bin Salman’s draconian regime.”

Cambridge’s committee on benefactions and external and legal affairs, which scrutinises proposals for reputational risk, earlier this year approved a request by the Judge business school to seek a “memorandum of understanding” (MoU) with the Saudi ministry of defence to develop executive education courses.

A spokesperson for the university declined to comment on the letter and referred to a previous statement by the business school, which said: “Cambridge Judge business school has not signed such an MoU with the Saudi Arabia defence ministry.”

Documents seen by the Guardian show that Judge business school officials have sought and received permission from the benefactions committee “to enter into a memorandum of understanding” with the Saudi ministry, at a meeting in January. Prentice is chair of the benefactions committee.

Senior academics at Cambridge said they were “horrified” by the proposal, while Jemimah Steinfeld, the chief executive of Index on Censorship, described it as “repugnant”.

“Even if an agreement is fleshed out to state academic freedom would be protected, self-censorship has a terrible habit of creeping in when money is on the line,” Steinfeld said.

The letter by the imprisoned scholars’ sons added: “In our view, the only meaningful safeguard is to insist that Saudi Arabia end its repression of freedom of expression and release those who are being prosecuted for nothing more than their beliefs, as a pre-condition for engagement.”