President Donald Trump's plan to build a wall on the border with Mexico ran into more trouble after California decided to sue his administration over the controversial issue. In the latest salvo in Trump's ongoing battle to have his vision implemented, the lawsuit, filed by California Attorney General Xavier Becerra, says that the Republican's proposed plan violates federal environmental laws. The lawsuit - supported by the California Coastal Commission - also claims that the US leader's proposal seeks to exploit California state laws.

Trump's main campaign promise

The border was Trump's signature declaration during his presidential campaign, and it helped him win support from conservative voters concerned by illegal immigration. However, the proposed wall received widespread condemnation from pro-immigrant associations in California. The state that has been largely under Democratic political leaders, shelters the United State's largest number of undocumented immigrants. Earlier this year, the US government moved to rid itself of several environmental laws with the aim of ensuring "expeditious" construction of barriers and roads along the US-Mexico border near San Diego. According to The Independent and Fox News, the California AG said that not even the President of the United States had the leeway to ignore rules.

During a press conference, Mr. Becerra stated that his state respects US immigration policy, and is aware that the issue is a federal problem. He, however, added that if Trump wants to implement his immigration policy in California, he should do so by adhering to the rule of law.

Push for funding for border wall

For Trump to implement his plan, his administration would have to convince the US Congress to allocate the required funding.

So far, the Congress has been reluctant to bankroll the border wall. Trump went even as far as threatening to shut down the government if a budget to build the wall was not passed, but his threats fell on deaf ears. His government also tried to show its plan to forge ahead with the scheme by announcing it had awarded contracts for designs of the wall, but its efforts have encountered resistance at every turn.

Since his announcement that he was negotiating an immigration middle-ground with top Democrats, the US President has provided conflicting messages on whether funding for his pet project would be part of any agreement. Facing pressure from their supporters, Democrats do not look inclined to accommodate Trump.