California has appointed an unauthorised immigrant to an official state post, a first that also functions as the state’s latest act of defiance against Donald Trump.

State Senate President pro Tem Kevin de León, a Los Angeles Democrat who is running for the US Senate on an anti-Trump platform, announced that 33-year-old attorney Lizbeth Mateo would serve as a member of the California Student Opportunity and Access Program Project Grant Advisory Committee. The appointment is unpaid.

“While Donald Trump fixates on walls, California will continue to concentrate on opportunities,” Mr de León said in a statement.

Born in Oaxaca, Mexico, Ms Mateo came to Los Angeles with her parents when she was 14. She said in a statement that her experience as an undocumented, first-generation college student would inform her work.

“While undocumented students have become more visible in our state, they remain underrepresented in places where decisions that affect them are being made,” Ms. Mateo said.

Dominated politically by Democrats who are sympathetic to immigrants, California has a long history of both shielding from deportation and offering new rights to immigrants in the country illegally.

Inside California's largest detention centre Show all 9 1 /9 Inside California's largest detention centre Inside California's largest detention centre Backs turned: Adelanto faces complaints that it does not allow inmates sufficent visits Reuters Inside California's largest detention centre Barbed issue: the facility is the focus of protests by immigrant rights groups Reuters Inside California's largest detention centre ‘Aliens’: ICE agents are empowered to round up suspected illegal immigrants Reuters Inside California's largest detention centre World class: the facility is run by private operator The Geo Group Reuters Inside California's largest detention centre Limbo: people have gone on hunger strike to protest prolonged imprisonment Reuters Inside California's largest detention centre Colours: inmates wearing blue have no or minor criminal conviction – the rest wear orange or red Reuters Inside California's largest detention centre Domino effect: according to ICE, arresting ‘criminal aliens’ is a priority that predates Trump’s presidency Reuters Inside California's largest detention centre Uncertainty: Around 240 of the detainees at Adelanto are women Reuters Inside California's largest detention centre An ICE detainee rests his hands on the window of his cell in the segregation wing at the Adelanto immigration detention center, which is run by the Geo Group Inc (GEO.N), in Adelanto, California, Reuters

In recent years, the state has passed laws allowing undocumented immigrants to secure drivers licenses and to practice law. After the latter measure passed, the California Supreme Court ruled in favour of an undocumented immigrant named Sergio Garcia who had been fighting for a law license.

Governor Jerry Brown last year signed a so-called “sanctuary” law that bars law enforcement from cooperating with Immigration and Customs Enforcement (ICE) unless federal agents have a warrant or immigrants of interest to ICE have been convicted of serious crimes.

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The law, specifically crafted to counteract the Trump administration’s crackdown on illegal immigration, has prompted a legal challenge from the Department of Justice and frequent denunciations from Mr Trump.

“California sanctuary policies put the entire nation at risk”, the President said this week during his first visit to California since taking office. “They’re the best friend of the criminal”.