After the most expensive campaign in U.S. history, President Obama is dropping his principled objection to some forms of political fundraising to help pay for the post-election party.

ABC News has learned that the Presidential Inaugural Committee will accept unlimited corporate donations to help fund Obama's inauguration festivities next month, reversing a voluntary ban on the money he imposed on the inaugural four years ago and during the 2012 Democratic National Convention.

Obama will also allow individuals to contribute up to the legal maximum for the 2013 inauguration - $250,000 - lifting a $50,000 cap he voluntarily imposed in 2008, sources said.

The shift appeared to be driven by fundraising challenges in the wake of a multi-billion dollar campaign. Obama and GOP nominee Mitt Romney each raised north of $1 billion for the election cycle - historic highs - according to Federal Election Commission filings released Thursday.

Obama's 2009 inaugural celebration cost $47 million.

Officials said cost considerations for the 2013 festivities would mean less elaborate events than four years ago. There will not be a star-studded concert on the National Mall, for example, and there will be fewer inaugural balls.

A spokeswoman for the committee said Obama will still not accept donations from lobbyists or PACs, or allow any individuals or corporations to formally sponsor specific inaugural events, such as the parade.

"Our goal is to make sure that we will meet the fundraising requirements for this civic event after the most expensive presidential campaign in history," said Addie Whisenant. "To ensure continued transparency, all names of donors will be posted to a regularly updated website."

Whisenant told ABC News that the Inaugural Committee will "fully vet" all individual and corporate donors and that "contributions from those not meeting the vetting standard will not be accepted." Among those barred by law are foreign nationals and corporations; the committee says it will also reject funds from companies that have outstanding TARP payments.

Obama's reversal is not the first time he has dropped self-imposed campaign financing rules meant to "change business as usual in Washington." Earlier this year, Obama dropped his long-standing opposition to super PACs, giving his approval for top aides to support Priorities USA Action. During the 2008 campaign, he broke a standing promise to accept public financing for the general election.

The Inaugural weekend will kick off on Saturday, Jan. 19, with a National Day of Service that will include participation from the First Family, Vice President Biden, and members of the Cabinet - a tradition started by the Obamas in 2009.

On Jan. 20, as is constitutionally required, Obama will be sworn in during a private ceremony. A public-swearing in, parade and inaugural balls will take place on Monday, Jan. 21.

Leading the fundraising effort for inauguration are four of Obama's most loyal surrogates and financiers: Former ambassador Matt Barzun, the Obama campaign's national finance chair and a top bundler; actress Eva Longoria, an Obama campaign co-chair and bundler; Jane Stetson, finance chairwoman of the DNC; and businessman Frank White.

News of Obama's shift on inaugural financing was first reported by Politico's Donovan Slack.

UPDATE: A nonpartisan government watchdog group, Public Citizen, assailed Obama's decision to accept unlimited corporate funding for his 2013 inauguration, calling the arrangement "Obama Inc."

"The American people have a right to expect something other than an inauguration brought to them by Bank of America," said Public Citizen president Robert Weissman.

"Every corporation's donations create a conflict of interest, because they all have business before the government in one way or the other," he said. "The problem with donations from lobbyists is that they expect something in return for their contribution. The situation is exactly the same with corporate contributors, virtually all of whom employ lobbyists."

Weissman called it doubly disappointing that the "corporate-funded" inaugural activities will fall on the anniversary of the U.S. Supreme Court decision in "Citizens United," which opened the door to unlimited corporate spending in campaigns - a decision Obama has decried.

Public Citizen appealed to Obama last week with a petition of 30,000 signatures to refuse corporate money for the inauguration.

This post has been updated.