Press secretary: Obama plan 'legally unassailable' November 21, 2014 -- Updated 2230 GMT (0630 HKT) President Barack Obama announced his immigration plans on Thursday night Republicans say the President's actions are an overreach, and some say they'll sue Obama's press secretary said Friday that the proposal is on solid legal footing Washington (CNN) -- As Republicans raise the idea of a court challenge against President Barack Obama's immigration action, White House spokesman Josh Earnest argued Friday that the President's executive orders stand on solid legal ground. "What the president announced last night is legally unassailable," he told CNN's Chris Cuomo on "New Day." Obama announced his plans Thursday night to legally permit up to 5 million undocumented immigrants to stay in the United States temporarily, bypassing Congress after lawmakers failed to pass comprehensive reform. Earnest reiterated a point the White House has fervently tried to make in recent days, that previous presidents have used executive authority on the issue of immigration. But critics argue that Obama's action amounts to overreach, saying his latest decision goes beyond what former presidents have done. Republican lawmakers vowed to aggressively pursue pushback against the new orders, with some proposing efforts to defund Obama's plan through spending legislation, while others called for lawsuits. Earnest, however, said that if the Republican-led House of Representatives would approve the Senate's reform bill that was passed last year with bipartisan support, then "the president would sign it right away." "He'd tear up his own executive actions," Earnest continued, before recapping a line Obama made in his speech Thursday night. "The truth is the closest thing we have to amnesty right now is doing nothing and that's exactly what House Republicans are doing," he said.