A group of Democratic senators called Tuesday for the Department of Transportation to end an "unacceptable" delay in implementing a ban on electronic cigarettes on airplanes. 

The senators said Tuesday in a letter to Transportation Secretary Anthony Foxx that the agency is two years behind schedule in finalizing rules that would ban the use of e-cigarettes during flights. 

"While many major carriers have decided to prohibit the use of electronic cigarettes, federal regulations still allow these products to be used during flight," the lawmakers wrote. 

"The Department of Transportation first published proposed rules to prohibit the use of electronic cigarettes on aircraft on September 15, 2011," the senators continued. "It is unacceptable that it has been more than two years and this rule has yet to be finalized."

The letter was signed by Sens. Barbara Boxer (D-Calif), Dick Durbin (D-Ill.), Tom Harkin (D-Iowa), Richard Blumenthal (D-Conn.), Sherrod Brown (D-Ohio), Jack Reed (D-R.I.) and Edward J. Markey (D-Mass). 

To read the full article, click the link below.