(CNN) Donald Trump's son-in-law, Jared Kushner, will be senior adviser to the president, a senior transition official told CNN Monday.

The 35-year-old businessman-turned-political strategist played a key part in his father-in-law's presidential campaign and his new position is expected to test the limit of federal anti-nepotism rules. The move comes ahead of a Wednesday news conference in which Trump is expected to detail how he plans to manage his company's potential conflicts-of-interest after he enters the White House.

Kushner plans to resign from the management positions he holds at his companies, including as CEO of Kushner Companies, publisher of The Observer and positions with other organizations, and will divest from a "significant number" of his assets to comply with government ethics rules, Kushner's attorney Jamie Gorelick told CNN on Monday.

Kushner also will not take a salary as he steps into the West Wing job, an official who briefed on behalf of the transition told reporters later on Monday.

Top Democrats on the House Judiciary Committee issued a statement within hours of Kushner's appointment calling on the Justice Department and the Office of Government Ethics to review the appointment's legality in light of the anti-nepotism statute.

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