The onetime DEA heads plan to issue joint statements Tuesday saying the Obama administration has reacted too slowly and should immediately sue to force the states to rescind the legislation.
The Associated Press received an advance copy of the statement Monday.
One of the former DEA administrators, Peter Bensinger, told the AP that the more time goes by, the harder it'll be to stop the two states. Marijuana is illegal under federal law.
Bensinger, who lives in the Chicago area, said the government must immediately sue the states or risk creating "a domino effect" in which other states follow suit.
"My fear is that the Justice Department will do what they are doing now: do nothing and say nothing," said Bensinger. "If they don't act now, these laws will be fully implemented in a matter of months."
U.S. Attorney General Eric Holder told a meeting of state attorneys general last week that he is still reviewing the laws but that his review is winding down. Asked Monday for a comment on the criticism from the former DEA administrators, Holder spokeswoman Allison Price would only say, "The Department of Justice is in the process of reviewing those initiatives."
The department's review has been under way since shortly after last fall's elections. It could sue to block the states from issuing licenses to marijuana growers, processors and retail stores, on the grounds that doing so conflicts with federal drug law. Alternatively, Holder could decide not to mount a court challenge.
The ex-DEA heads are issuing the statements though the Florida-based Save Our Society from Drugs, a national group lobbying against legalization. One of the group's spokesmen is based in Chicago.
The former DEA administrators are Bensinger, John Bartels, Robert Bonner, Thomas Constantine, Asa Hutchinson, John Lawn, Donnie Marshall and Francis Mullen. They served for both Republican and Democratic administrations.
Holder is scheduled to appear Wednesday before a U.S. Senate judiciary committee hearing. The former DEA chiefs want senators to question Holder on the legalization issue.
Advocates of legalization have welcomed Colorado and Washington's new laws, arguing that criminalizing drugs creates serious though unintended social problems. The ex-DEA heads say they disagree with that view.
After votes last fall, Colorado and Washington became the first states to legalize marijuana's recreational use -- putting federal authorities in a quandary over how, or whether, to respond.
Washington state officials responsible for creating a regulated marijuana system have said they are moving forward with a timetable of issuing producer licenses by August.
Bensinger -- who served as DEA administrator under Presidents Gerald Ford, Jimmy Carter and Ronald Reagan -- said the supremacy of federal law over state law when it comes to drug laws isn't in doubt.
"This is a no-brainer," he said. "It is outrageous that a lawsuit hasn't been filed in federal court yet."
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Copyright 2013 The Associated Press.