President Obama is ramping up pressure on Republicans to avoid a post-midnight government shutdown.

WASHINGTON – President Obama blamed the "extreme right wing" of the Republican Party for a budget standoff that has pushed the government to the edge of the first shutdown in 17 years, and he made one last plea Monday to House Republicans to pass a spending bill before a midnight deadline.

“One faction of one party in one house of Congress in one branch of government doesn't get to shut down the entire government just to re-fight the results of an election,” Obama said in a brief appearance in the White House briefing room.

Speaking for several minutes without taking questions, the president outlined the functions that would continue in a shutdown – including Social Security, Medicare, national security and public safety – and those that would be curtailed, including national parks, NASA, federal lending programs and recovery efforts helping victims of Superstorm Sandy. Obama said the impact would be a setback to a recovering economy.

PHOTOS: 2013's memorable political moments

"The idea of putting the American people's hard-earned progress at risk is the height of irresponsibility and it doesn't have to happen. Let me repeat this. It does not have to happen. All of this is entirely preventable if the House chooses to do what the Senate has already done," he said.

The president also noted that, despite Republican efforts to kill his healthcare law, the online insurance marketplaces will roll out Tuesday as scheduled. "The Affordable Care Act is moving forward. That funding is already in place. You can't shut it down," he said.

The president also met at the White House with his Cabinet on Monday evening. “We're going to be discussing the impacts, potentially, of a shutdown and how all of these various agencies will be managing to make sure the core essential functions continue,” he said.

But he also said they would discuss how to help the hundreds of thousands of federal employees who could be furloughed “try to manage what's going to be a very difficult potential situation.”

Follow Politics Now on Twitter and Facebook

kathleen.hennessey@latimes.com

Twitter: @khennessey