U.S. Sen. Bernie Sanders (I-Vt.) said today he will introduce legislation to break up banks that have grown so big that the Justice Department has not pursued prosecutions for fear an indictment would harm the financial system.

The 10 largest banks in the United States are bigger now than before a taxpayer bailout following the 2008 financial crisis. At the time Congress, over Sanders’ objection, approved a $700 billion bank rescue because of concerns by some that the financial institutions were too big to fail. Another $16 trillion from the Federal Reserve propped up financial institutions.

Attorney General Eric H. Holder Jr. now says the Justice Department may not pursue criminal cases against big banks because filing charges could “have a negative impact on the national economy, perhaps even the world economy.”

“In other words,” Sanders said, “we have a situation now where Wall Street banks are not only too big to fail, they are too big to jail. That is unacceptable and that has got to change because America is based on a system of law and justice.”

U.S. banks have become so big that the six largest financial institutions in this country (J.P. Morgan Chase, Bank of America, Citigroup, Wells Fargo, Goldman Sachs, and Morgan Stanley) today have assets of nearly $9.6 trillion, a figure equal to about two-thirds of the nation’s gross domestic product. These six financial institutions issue more than two-thirds of all credit cards, over half of all mortgages, control 95 percent of all derivatives held in financial institutions and hold more than 40 percent of all bank deposits in the United States.

Sanders’ legislation would give Treasury Secretary Jacob Lew 90 days to compile a list of commercial banks, investment banks, hedge funds and insurance companies that he deems too big to fail. The affected financial institutions would include “any entity that has grown so large that its failure would have a catastrophic effect on the stability of either the financial system or the United States economy without substantial government assistance.”

Within one year after the legislation became law, the Treasury Department would be required to break up those banks, insurance companies and other financial institutions identified by the secretary.

“If an institution is too big to fail, it is too big to exist,” Sanders said. “No single financial institution should be so large that its failure would cause catastrophic risk to millions of American jobs or to our nation’s economic wellbeing. No single financial institution should have holdings so extensive that its failure could send the world economy into crisis,” Sanders said. “We need to break up these institutions because they have done of the tremendous damage they have done to our economy.”