New York City Mayor, Don Blasio, has urged all government pension funds in New York and across the US to divest from funds that include assault weapon manufacturers. In his call he is joining a growing campaign which is urging institutional investors to divest from, and for individual Americans to stop their pension funds investing in, the publicly listed gun manufacturers.

Responding to the latest mass killings in America, blamed on terrorists, Blasio, said, “It is the public and private investment in gun manufacturers that helps put these weapons into the hands of killers. It should come to a halt until gun manufacturers can ensure they will sell assault weapons only to the military and law enforcement agencies, not civilians.

Two of New York's public pension funds, the New York City Employees Retirement System, and the New York City Teachers Retirement System have already divested their holdings in gun manufacturers. Blasio said he was now instructing the other three New York pension funds to divest from gun manufacturers: " if no verifiable assurance is given that assault weapons will not be sold to civilians. There is plenty of money to be made manufacturing guns and rifles specifically designed for hunting and home defence. A restriction on civilian ownership of assault weapons will make it much harder for criminals, terrorists and people suffering from mental illness to obtain these killing machines."

The Campaign to Unload has been putting pressure on institutional investors and pension funds to stop investing in the three publicly traded gun companies -Sturm Ruger, Smith & Wesson, and Olin. Working with the States United to Prevent Gun Violence it has launched the unload your 401k website which allows individuals in the US to find out if there personal pension provider is investing in these gun manufacturers and to then put pressure on these institutional investors to divest these stocks. This campaign has been gathering momentum and high profile backers include US rapper and actor Snoop Dogg and other US sports and music stars who came together earlier this year to pledge they would be asking for their 401k plans to stop investing in gun manufacturers.

The power to push the pension funds to act ultimately lies with Comptroller Scott Stringer who oversees the five pension boards on behalf of the municipal unions representing teachers, school administrators, police, firefighters and civil servants. In 2013, fo, Stringer's predecessor John Liu announced that the the New York City Employees’ Retirement System, which represents civil servants, had divested $13.5 million in stock holdings of gun and ammunition manufacturers.