Sens. Bernie Sanders, I-Vt., and Elizabeth Warren, D-Mass., have asked the Federal Communications Commission to investigate big cable and broadband providers for engaging in monopolistic practices to push consumers to pay "ridiculous prices" for services.

Addressed to FCC Chairman Tom Wheeler, the senators wrote that due to a number of mega-mergers, only 37 percent of Americans "have more than one option for high-speed broadband providers." The limited options means that companies are able "to charge ridiculous prices and add hidden fees," the letter says.

Sens. Ed Markey, D-Mass., and Al Franken, D-Minn., joined Sanders and Warren in writing the letter.

"Many Americans have very few, if any, options when it comes to choosing their local cable and Internet provides," the senators said. "As the telecommunications industry has become increasingly concentrated, this lack of choice has resulted in huge price increases and often poor services for customers."

In noting that the FCC is required to keep track of how much telecommunications firms charge consumers, the senators requested that Wheeler hand over the information regarding how much Americans pay on average for Internet and cable services, including averages based on state and company. The senators also want to know how much urban Americans pay compared to rural Americans.

"The recent increased concentration in the cable and Internet industries has created a de facto monopoly where substantial price increases have become the norm," Sanders wrote in a separate press release. "Currently, America ranks 25th worldwide for broadband speed, and we pay more for poorer quality broadband than customers in Slovakia Estonia, South Korea, and the U.K."

The letter comes as the FCC begins to consider a new merger between Time Warner Cable and Charter Communications, which the senators say would only exacerbate the problem. Recent increases in the price of Time Warner services indicates that the company is already insulated from normal market pressures, the senators say. They cited Time Warner's modem rental charges increasing by 203 percent since they were introduced in 2012.

Read the entire letter here.