President Barack Obama speaks to the media about the possibility of a government shut down in Brady Press Briefing Room at the White House September 30. (Photo by Mark Wilson/Getty Images)

President Barack Obama speaks to the media about the possibility of a government shut down in Brady Press Briefing Room at the White House September 30. (Photo by Mark Wilson/Getty Images)

President Barack Obama addressed the nation today to explain that the looming federal government shutdown, which would leave at least 800,000 civilian employees without a paycheck, “doesn’t have to happen.”

“Of all the responsibilities the Constitution endows to Congress, two should be fairly simple: pass a budget, and pay America’s bills,” Obama said from the Brady Press Briefing Room. “But if the United States Congress does not fulfill its responsibility to pass a budget today, much of the United States government will be forced to shut down tomorrow.”

Obama then explained what would continue (Social Security checks, mail, prison guards) and what would stop.

“Office buildings would close. Paychecks would be delayed. Vital services that seniors and veterans, women and children, businesses and our economy depend on would be hamstrung,” the president said. “Business owners would see delays in raising capital, seeking infrastructure permits, or rebuilding after Hurricane Sandy. Veterans who’ve sacrificed for their country will find their support centers unstaffed. Tourists will find every one of America’s national parks and monuments, from Yosemite to the Smithsonian to the Statue of Liberty, immediately closed. And of course, the communities and small businesses that rely on these national treasures for their livelihoods will be out of customers and out of luck.”

Obama also explained that the federal government is America’s largest employer, so millions of people would be left in a lurch.

“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,” Obama said. “All of this is entirely preventable if the House chooses to do what the Senate has already done — and that’s the simple act of funding our government without making extraneous and controversial demands in the process, the same way other Congresses have for more than 200 years.”

One “extraneous and controversial” demand is, of course, the repeal of the Affordable Care Act, or Obamacare.

“Let me be clear about this. An important part of the Affordable Care Act takes effect tomorrow no matter what Congress decides to do today,” Obama said. “The Affordable Care Act is moving forward. That funding is already in place. You can’t shut it down.”

He later said, “You don’t get to extract a ransom for doing your job; for doing what you’re supposed to be doing anyway; or just because there’s a law there that you don’t like.”

Watch Obama’s full speech below.