WASHINGTON (Reuters) – President Donald Trump on Friday nominated Columbia University law professor Robert Jackson, an advocate for public disclosure of political spending by companies, for a vacant seat on the five-member U.S. Securities and Exchange Commission.

If the nomination is approved by the U.S. Congress, Jackson would fill a spot reserved for a Democrat.

His nomination, announced in a White House statement, follows a July decision by Trump to tap Hester Peirce, a former congressional aide, for a Republican seat on the commission.

Approval of the nominees would bring the agency tasked with policing and writing rules for Wall Street to full strength and clear the way for SEC Chairman Jay Clayton to push ahead on an agenda of reducing the regulatory burden on public companies.

Jackson is known for his advocacy work in trying to advance new rules at the SEC that would force public companies to disclose their political spending to investors.