The US Transportation Security Administration (TSA) has decided to delay allowing passengers to bring small knives and other objects, such as sporting equipment, aboard commercial aircraft.

TSA was scheduled to rescind its prohibition, starting Thursday, on carrying items such as pocket knives through airport security checkpoints and into aircraft cabins. The decision to allow small knives, announced by TSA administrator John Pistole in March, led to a great deal of public controversy and was opposed by several major US airlines and their flight attendant unions.

“In order to accommodate further input from ... representatives from the aviation community, passenger advocates, law enforcement experts and other stakeholders, TSA will temporarily delay implementation of changes to the Prohibited Items List, originally scheduled to go into effect April 25,” TSA said in a statement. The agency did not say how long the delay will last.

US Sen. Lisa Murkowski (R-Alaska) said in a statement that she has been told by US Homeland Security secretary Janet Napolitano that, even though a delay has been put into effect, allowing “small knives on planes is inevitable.”

Murkowski and Sen. Chuck Schumer (D-NY) have co-written a letter to the Dept. of Homeland Security office of inspector general asking that it “scrutinize and investigate the policy change.” They wrote, “We are quite concerned at the prospect that checkpoint screenings slow to a crawl as [TSA screeners] and passengers disagree over the length or width of knives or knives which do not meet policy. It is our understanding the [screeners] would not be provided with measuring tools to quickly determine whether or not a knife is acceptable. Instead, they would simply rely on 15 minutes of training, during which they would view pictures of acceptable and unacceptable knives.”