Sen. Al Franken (D-Minn.) is pushing the Justice Department to protect the open Internet as it considers a proposed deal between Comcast and Time Warner Cable.

In his letter to the Justice Department, which is evaluating the proposed acquisition, Franken touted the benefits of net neutrality.

"Because of net neutrality and settlement-free peering, the website for a small hardware store in rural Minnesota loads as quickly as the website for a big, national chain ... and an email from a constituent in Duluth gets to me as quickly as an email from my bank," he wrote.

A deal combining the two largest cable companies could harm net neutrality by giving Comcast too much leverage, Franken said.

"I am very concerned that Comcast could use its clout in the broadband market to dictate the content consumers receive and the prices they pay, and these concerns are only intensified by Comcast’s proposal to acquire Time Warner Cable."