Protesters have converged in cities around the US to condemn Donald Trump’s declaration of a national emergency to fund his planned US-Mexico border wall.

Organised by the liberal group MoveOn and others, the demonstrations took the occasion of Presidents Day to attack Mr Trump’s proclamation as undemocratic and anti-immigrant.

“Trump is the national emergency!” chanted a group of hundreds lined up at the White House fence, where some held up large letters spelling out “stop power grab”.

In Fort Worth, Texas, a group carried signs with messages including “no wall! #FakeTrumpEmergency”.

In Newark, New Jersey, Kelly Quirk told a gathering that “democracy demands” saying “no more” to the president.

“There are plenty of real emergencies to invest our tax dollars in,” said Ms Quirk, part of a local progressive group called Soma Action.

There were some counter-protesters, including in Washington, where there was a brief scuffle in the crowd.

Protesters at the White House
Protesters at the White House (Carolyn Kaster/AP)

Mr Trump’s declaration on Friday shifts billions of dollars from military construction to the border.

The move came after Congress did not approve as much as he wanted for the wall, which the Republican considers a national security necessity.

His emergency proclamation calls the border “a major entry point for criminals, gang members and illicit narcotics”.

Illegal border crossings have declined from a high of 1.6 million in 2000, but 50,000 families are now entering illegally each month, straining the US asylum system and border facilities.

Mr Trump’s declaration is facing legal challenges, and critics have argued he undercut his own rationale for the emergency declaration by saying he “didn’t need to do this” but wanted to get the wall built faster than he otherwise could.

“President Trump declared a national emergency in order to spend billions of taxpayer dollars on his border wall obsession,” Manar Waheed of the American Civil Liberties Union told protesters rallying in a Washington park before heading to the nearby White House fence.

The ACLU has announced its intention to sue Mr Trump over the issue.

Ana Maria Archila, co-executive director of the left-leaning Centre for Popular Democracy, said the president had undertaken to “steal money that we desperately need to build a country of our dreams so that he can build a monument to racism along the border”.

At one point during the rally, a counter-protester walked through the crowd toting a sign saying “finish the wall” on one side and “protect the poor” on the other.

Another man snatched his sign from him, sparking a short scuffle.