Donald Trump, the US president, has hit out at the "radical Left" after 16 states launched a legal challenge against him declaring a national emergency to pay for his border wall.
After a failed attempt to convince Congress to sign off on his demand for $5.7 billion (£4.4 billion) to build a structure along the southern border with Mexico, Mr Trump announced that he would be invoking the controversial emergency power on Friday.
Through the new power his administration plans to use $8 billion from government departments to fund the border wall, a key promise from his 2016 election campaign. The money will be diverted from budgets for military construction projects and efforts to fight illegal drug trafficking.
But in a lawsuit filed in California on Monday night, a coalition of 16 states has sought a preliminary injunction that would prevent the president from using the emergency powers until a court has ruled whether or not the declaration is constitutional.
Accusing Mr Trump of “an unconstitutional and unlawful scheme,” the suit argues the states are trying “to protect their residents, natural resources, and economic interests from President Donald J. Trump’s flagrant disregard of fundamental separation of powers principles engrained in the United States Constitution.”
In addition to California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Virginia, and Michigan have all joined the lawsuit. With the exception of Maryland, all the states involved have Democratic governors.
Mr Trump tweeted Tuesday: "As I predicted, 16 states, led mostly by Open Border Democrats and the Radical Left, have filed a lawsuit in, of course, the 9th Circuit! California, the state that has wasted billions of dollars on their out of control Fast Train, with no hope of completion, seems in charge!"
The president was also referencing a decision by California Governor Gavin Newsom last week to cancel a high-speed rail line between Los Angeles and San Francisco because of spiraling costs. Mr Trump claims the "failed Fast Train project" was beset by "world record setting" cost overruns and had become "hundreds of times more expensive than the desperately needed Wall!"
The lawsuit argues that Congress has already passed laws, which have been signed by the president, appropriating the funds and the US Constitution requires the president to faithfully execute them.
National Emergencies | When and how they've been used in the past
The states also said Mr Trump’s order would cause them to lose millions of dollars in federal funding for national guard units dealing with counter-drug activities and the loss of funding for military construction projects would damage their economies.
The lawsuit argues that the government’s own figures prove there is no emergency at the southern border, with "unlawful entries" at a near 45-year low.
The complaint was filed in a San Francisco-based court which has repeatedly ruled against the president in key cases on immigration and the environment.
If the outcome is appealed, the case then goes to the Court of Appeals for the ninth circuit, which Mr Trump has previously called a "thorn in our side". It may eventually end up at the conservative-leaning Supreme Court.
At a glance | Donald Trump’s border wall
Mr Trump has said that his declaration is allowed under a 1976 law called the National Emergencies Act and the White House has argued the law has been used multiple times in recent history.
But critics of the move, including some Republicans, have argued previous uses have involved emergencies such as human rights violations rather than redistributing money Congress had intended for other purposes.
During interviews on Monday Xavier Becerra, California’s attorney general who is spearheading the legal challenge, said the lawsuit would use Mr Trump’s own words against him as evidence that there was no national emergency to declare.
Democrats in Congress have said they will also put forward a resolution to repeal the national emergency and say they expect some Republicans will support it.