The lawsuit targets three laws in particular: the Immigrant Worker Protection Act (HB 450), the Inspection and Review of Facilities Housing Federal Detainees law (AB 103); and the California Values Act (SB 54).
The California Peace Officers Association said the conflicting rules are creating confusion for police on the street and are now looking for Sessions to clarify those issues.
Sessions has prioritized cracking down on cities that fail to comply with federal immigration authorities - called "sanctuary cities" - in his time as attorney general, following through on campaign promises and platforms President Trump made, as CBS News' Paula Reid has reported.
Sessions said several California state laws prevent U.S. Immigration and Customs Enforcement officers from making deportation arrests and singled out elected officials for their actions.
Becerra defended the law under the 10th Amendment of the U.S. Constitution, which he said gives California the right to decline to participate in civil immigration enforcement.
State officials say the policies increase public safety by promoting trust between immigrant communities and law enforcement, while allowing police resources to be used to fight other crimes.
The U.S. Supreme Court reinforced the federal government's primacy in enforcing immigration law when it blocked much of Arizona's tough 2010 immigration law on similar grounds. Pro Tem Kevin de Leon called Sessions' policies "white nationalism and white supremacy". It accuses the state of blocking federal immigration enforcement efforts. "We're not in the business of deportations", Becerra said.
"This is basically going to war against the state of California", Gov.More news: Nigeria to benefit from United States $533m charity fund for Africa
But what Sessions said next really put California on notice. He had particularly strong words for Oakland Mayor Libby Schaaf, who issued an unusual public warning last month about an immigration operation. Those who have outstanding orders of deportation, or who returned to the USA after being deported, are subject to immediate removal from the country, said the agency in a press statement, adding that the remaining individuals are in ICE custody awaiting a hearing before an immigration judge, or pending travel arrangements for removal in the near future.
In Sacramento this morning, Sessions questioned California's so-called "sanctuary state" policies. Schaaf said Tuesday that the city would "continue to inform all residents about their constitutional rights".
The Justice Department filed a lawsuit against California, Brown and Attorney General Xavier Becerra yesterday. "Her actions support those who flout our laws and boldly validate the illegality", he said.
"There is no nullification; there is no secession", Sessions said.
In the time since Donald Trump won the presidential election, there has been an increasing amount of tension between lawmakers in Washington DC and lawmakers in California.
"I understand that we have a wide variety of political opinions out there on immigration, but the law is in the books and its purposes are clear and just".
"Those are 800 wanted criminals that are now at large in that community - 800 wanted criminals that ICE will now have to pursue by other means, with more difficulty in risky situations - all because of one irresponsible action", Sessions said.