Mayor Michelle Wu continues to draw a firm line of defense of the city's immigration policy following her testimony in D.C. last week, while acknowledging the power Congress has to follow through with threats made to sanctuary cities and their mayors.

"This is extremely serious. And as much as it can seem like a sort of show or production when you're watching it, Congress has power," Wu said on Boston Public Radio's "Ask the Mayor" on Tuesday morning.

Wu argued during the six-hour hearing last week that while Boston's Trust Act bars local law enforcement from cooperating with federal immigration officials, the city continues to work with federal law enforcement on criminal cases. During her testimony, Wu also suggested Congress pass comprehensive immigration reform.

Republicans in Congress maintain that sanctuary policies violate federal law, and have threatened to refer sanctuary mayors to the Department of Justice for investigation. Republican U.S. Rep. James Comer, who invited Wu and three other mayors to D.C. last week, suggested federal lawmakers might attempt to withhold federal funding from sanctuary cities if they don't change their policies.

"People who are in the federal government have real power to enact consequences, whether that's on federal funding or whether that is to follow through with some of the threats around prosecutions of individual people or the referral to the Department of Justice," Wu continued. She said the city will continue to provide the House Oversight Committee with information and documents about city policies it requested.

As congressional Republicans continue to criticize sanctuary mayors, Republicans in Massachusetts continue to poke at Wu. The federal Small Business Administration announced last week that it would pull its Boston office, citing the city's immigration policy, and MassGOP Chair Amy Carnevale slammed Wu's message on Fox News.

"It's the height of irresponsibility for a big city mayor to welcome in criminal migrants, criminal illegal aliens," Carnevale said. "Certainly we've seen crime in Boston, highly-publicized incidents of criminal illegal aliens who have committed violent crimes."

Boston's policy does not prohibit local law enforcement from working with federal officials on criminal cases.

Wu added on Tuesday that ICE has not been in contact with Boston police to give any notice about the actions they're taking. "As far as we can tell, they are really still functionally sticking to the types of actions that happened under the Biden administration," Wu said.

"It does feel like much of this [has been] designed to silence people. To say, 'if you just sort of keep your mouth shut or quietly change your policies, then if you do what we want and satisfy the political wins right now, then maybe you'll have a chance of surviving better,'" the mayor added. "But that's not an alternative, that one, is acceptable for our community members, and two, that is how you can live for four years."

Wu has also taken flack from Democrats and Republicans since the hearing for the $650,000 bill her legal preparation racked up, which the city will pay for. Over the weekend, Wu's mayoral challenger Josh Kraft said he would have "looked at other more cost-effective measures" to prepare for the testimony, and would not have taken as many City Hall staffers to D.C. as Wu did.

"It is money that I very, very much wish we did not have to spend at all and time from my staff and my team that could have gone to much better, much more important things, but the stakes are high," Wu said.

"When there's threats to put me in jail, to take away funding, I needed to make sure that I was doing everything possible to represent our city well, to represent the policies with complete accuracy."