"The attacks on September 11, 2001 demonstrated that in the confined environment of an airplane, even a small blade in the hands of a terrorist can lead to disaster," he wrote. "The new, more permissive rules announced this week by TSA are opposed by the Flight Attendants Union Coalition and the Federal Law Enforcement Officers Association as an unnecessary change that needlessly places the lives of airline passengers and flight attendants at risk."

Last week, the TSA said that as of April 25, it would allow knives to be included in carry-on baggage as long as they do not lock; have blades no longer than 2.36 inches, or 6 centimeters; and are less than a half inch in width. TSA also said it would allow "novelty-sized and toy bats, billiard cues, ski poles, hockey sticks, lacrosse sticks and two golf clubs."

The agency said the change was part of a risk-based security approach that will allow TSA officers to focus on finding "higher threat items such as explosives."

The TSA first relaxed its rules on what can be included in carry-on luggage in 2005, when it allowed scissors and other sharp tools. In response to that change, Markey and other members of the House pushed legislation called the Leave All Blades Behind Act.

However, that bill went nowhere in the House. Markey, who is running for Massachusetts's open Senate seat, did not say whether he'd propose legislation to overturn the TSA's latest decision.