Slightly more than half of the $1.5 trillion attributed to tax reform -- $800 billion -- would come from letting the Bush tax cuts for the wealthiest Americans expire. The other $700 billion, the officials said, would come from other changes in tax law. Many of those measures, they acknowledged, will look very familiar because they have previously been proposed by Obama. Those would include limiting deductions for those making more than $250,000, ending tax preferences for owners of corporate jets, and ending oil and gas preferences. They said roughly $300 billion of the $700 billion would come from closing loopholes.

The administration has yet to offer a revenue estimate for a proposal the president will make that he will call "the Buffett rule," named after billionaire investor Warren Buffett. Buffett has lamented that he pays a lower tax rate than many of his employees; the president will call for a new minimum tax rate for individuals making more than $1 million to ensure that they pay at least at the same rate as middle-income taxpayers.

One senior official said the point of the Buffett rule is to establish "one of the principles that should govern how we undertake tax reform." The official stressed that the president on Monday will make "a broad call for tax reform" more than he is insisting on specific provisions. "These are suggestions for how it could be achieved," the official told reporters. "And it is meant to really start that debate."

To that end, the president will outline five principles he will insist on in tax reform: It should lower tax rates; it should cut wasteful loopholes and tax breaks; it should reduce the deficit by $1.5 trillion; it should boost job creation and growth; and it should "be consistent" with the Buffett rule in that everybody shares the burden.

On that last point, the president will stand his ground and issue a rare veto threat, said the official. "The president will make clear he is not going to support any plan that asks everything of some Americans and nothing from others," said the official. "He will say that he will veto any bill that takes one dime from the Medicare benefits seniors rely on without asking the wealthiest Americans and biggest corporations to pay their fair share."

The veto threat is a response to the hard line struck last week by House Speaker John Boehner, R-Ohio, in a speech he delivered on the economy. Boehner said tax reform should be on the super committee's agenda. But he ruled out any tax increases, saying they "are not a viable option for the joint committee." With the lines drawn, the White House expects much of what the president will outline to draw immediate opposition from the Republicans who run the House.

The White House also warned not to expect the president to offer up things that he had agreed to as compromises over the summer when he and Boehner were striving for a "grand bargain."