In this Jan. 22, 2013 file photo, Israeli Prime Minister Benjamin Netanyahu, center, prays with his sons Yair, background, and Avner, right, at the Western Wall. News that Yair Netanyahu is dating a non-Jewish Norwegian university student has generated interest among religious lawmakers who warn of assimilation. Uriel Sinai/AP Photo

Conservative Israeli groups and politicians are taking Prime Minister Benjamin Netanyahu to task over his son's alleged romance with a Norwegian who is not Jewish.

Netanyahu's son Yair, 23, is reportedly dating Sandra Leikanger, 25, a student at the Interdisciplinary Center outside Tel Aviv.

"It's a big problem," member of parliament Nissim Ze'ev from the ultra-Orthodox Shas Party told the Jerusalem Post. "As the prime minister of Israel and the Jewish people, he must display national responsibility via the values he presents inside his own household."

"Any Jew who wants to maintain his roots wants to see his son marry a Jewish girl," Ze'ev continued. "There is no shortage of beautiful, successful girls without sowing in the fields of others."

A photo published in both the Israeli and Norwegian media shows the couple smiling broadly, with the young Netanyahu's arm draped around the blonde Leikanger. The relationship was apparently serious enough for the elder Netanyahu to mention it to his Norwegian counterpart at last week's World Economic Forum in Davos, Switzerland, the Times of Israel reported.

"All I can say is that it is very unfortunate," said Moshe Feiglin, another member of the Israeli parliament from Netanyahu's Likud Party.

Reports of the relationship come as Netanyahu insists that Palestinians recognize Israel as a Jewish state as part of any peace agreement.

Yair's relationship with a non-Jew is not the first in his family. Netanyahu's second, British-born wife converted before they married in 1981 (Yair is the son of Netanyahu and his third wife, Sara.)

A far-right group that works to prevent inter-marriage between Jews and non-Jews, Lehava, wrote a scathing open letter to Netanyahu, calling on him to end his son's blossoming romance with Leiklanger, who reportedly comes from a Christian evangelical family.

"It is hard to believe that someone like you would let assimilation through the front door. The repercussions of your son's actions are far-reaching," the letter read, according to the Jewish Press website. "What kind of example of this for the son of the prime minister of the Jewish state that invests millions of dollars to prevent assimilation in the Diaspora, when assimilation is happening in his own home?"