Rep. John Culberson, R-Texas, says he's got a plan already in place that will likely eliminate sanctuary cities on Day 1 of the Trump administration.

At least 14 cities have spoken out defiantly in the wake of President-elect Donald Trump's surprise victory last month, saying they will continue to offer sanctuary to illegal criminal aliens regardless of Trump's attempts to end the sanctuaries, Culberson says.

But Culberson says the power of the purse is something Congress has at its disposal, and he intends to help Trump shut off the flow of federal dollars to sanctuary cities.

As chairman of the House Appropriations Committee's subcommittee on commerce, justice and science, Culberson said he acted on July 7 to notify the Department of Justice that it will need to change its policy.

"I have quietly installed an off-switch that the Department of Justice and Attorney General Loretta Lynch, at my request, changed official DOJ policy on July 7 and notified every state and city in the country that unless you comply 100 percent of the time with federal requests to deport criminal illegal aliens in your jails or prisons, you will lose all your federal law enforcement money," Culberson told Shannon Bream of Fox News.

"That's been the policy at the DOJ since July 7. I just didn't make a lot of noise about it because I didn't want the Obama administration to crawfish on us. So it's done. It's in place. And at noon on Jan. 20, if President Trump decides to do so, he could throw this switch I created and turn off all the federal law enforcement money to the top 10 sanctuary cities in America including the entire of state of California. New York City and Chicago? Lights out on Jan. 20 if he chooses."

Money flowing into local police departments and sheriff's agencies through the Community Oriented Policing Services, or COPS, grants and the Byrne-JAG grants, which fund miscellaneous police spending, would dry up, he says.

Some sanctuary cities have threatened to sue the federal government if the money is turned off. But to them, Culberson says, don't waste your time.

"Suing will not do them any good. This is their decision. This is the law now, as a result of what I've done on July 7. If you want federal money, follow federal law," he told Bream. "You must hand over every criminal illegal alien in your prisons to fed authorities to be deported immediately or you lose all your money."

Two of the most outspoken mayors have been Rahm Emanuel of Chicago and Bill De Blasio of New York City, along with mayors in San Francisco, Los Angeles, Philadelphia, Miami and Minneapolis.

Culberson says they'll have to put their money where their mouths are. The policy can even be enforced retroactively if need be.

"If Mayor Emanuel and Mayor De Blasio continue to refuse to comply with federal requests to hand over these dangerous criminal aliens in their custody, not only do they lose their money but the policy the DOJ put in place at my request says they will owe a refund of every dollar they ever received from these grant programs over the last 10 years," he said.

"That means the state of California, if they don't change, they will have to write us, the U.S. taxpayer, a check for $1.2 billion," Culberson continued. "New York City will owe us as taxpayers $211 million, and Rahm Emanuel, get your checkbook out, you're going to have to write America a check for $91.2 million if you don't comply with requests to hand over these dangerous criminals.

"And that's what we're talking about, Shannon, criminals convicted of crimes who were here illegally, who should be deported immediately when they finish their sentence, that's all we're talking about. Follow federal law or don't ask for federal money."

Watch Rep. John Culberson's full interview with Shannon Bream of Fox News:

Other grant programs could also be cut

Bream asked about non-criminal illegals and whether this policy change could apply to them as well.

"This off switch can actually be applied more broadly, to other grant programs, and a lawsuit won't help them because the Supreme Court has ruled repeatedly that accepting federal money is a discretionary act. You don't have to accept federal money, but if you take the federal money you have to accept all the strings that are attached to it," Culberson said. "So it won't do them any good to sue. "

He said other subcommittee chairmen on the House Appropriations Committee could enact similar measures to enforce laws affecting the agencies they oversee.

"Just give up the money. If you want to protect criminal aliens in your custody, don't ask for federal money, and that precedent I've created can apply much more broadly to other federal grant programs that are already in place," Culberson said. "This works not only for law enforcement grants but I believe it applies more broadly to community development grants , to other types of annual federal grant programs. The Trump administration if they choose to do so can make it apply much more broadly. But the days of taking federal money and not following federal law? Those days are over."

While illegals may be safe in Chicago, the law-abiding citizens don't have the same assurances. Year to date there have been more than 620 people shot and killed and 3,276 shot and wounded. Total homicides surpassed 700 last week.

Watch Rahm Emanuel give assurances to illegal aliens that they will be safe in his city, criminals or not.

"To be clear about what Chicago is, it always will be a sanctuary city," Emanuel said on Nov. 9. To all those who are, after Tuesday's election, very nervous, those filled with anxiety, you are safe in Chicago, you are secure in Chicago, and you are supported in Chicago."

Betsy Hodges, the mayor of Minneapolis who has been known to don a hijab when she meets with Somali refugees in her city, also issued a defiant statement: "I will continue to stand by and fight for immigrants in Minneapolis regardless of President-elect Trump's threats. I will not compromise the public safety of the people of Minneapolis to satisfy Trump's desire to put politics before public safety."

She forgot to mention the fact that it wasn't just immigrants but "illegal" immigrants she is committed to stand behind and protect, including many who are criminal illegal immigrants.

After the election, Trump said he planned to deport two to 3 million violent criminals. Not carrying out the detainers. One of those more than 2 million was an illegal who'd been deported five times before he came back and killed Kate Steinle in July 2015 in San Francisco, a sanctuary city that had sheltered him from deportation.

Constitutional expert Andrew Napolitano told Fox News' Megyn Kelly after the election that Trump can cut off sanctuary cities unilaterally but could implement conditions through Congress. And that congressional help is apparently already available thanks to Culberson.

"Well, look at how hard up the cities are for cash," Napolitano said. "The federal government is going to be dangling billions in front of them, and they're probably going to cave on this because they're going to want the cash. And if they don't cave and don't get the cash, there will be tremendous local political pressure on them to do so, but they are legally and constitutionally within their right to say to the fed government, 'We're not going to work for you.'"

Bream asked Culberson what he would say to those who would accuse him of cutting off vital funding to local communities.

"There's no question that this federal money is doing good in these local communities, but that's the local mayor or county judge's decision. It's the governor of California's decision," he said. "The Legislature in California gets to make a choice. If you want federal money, from now on you have to follow federal law. This is simple. It's not our decision.

"This has been the law by the way, Shannon, the law I'm enforcing as chairman, has been in effect since 1996, and it was never enforced until I used the power of the purse to force the DOJ to put this policy in place July 7, so this is up to the local folks. If the mayor refuses to follow federal law, get your checkbook out, Mayor Emanuel, you're going to owe us a refund."