Lenard said in a two-paragraph order that based on the government court filings, "there is a reasonable basis for believing such a group or class of persons may fail or may have failed to comply" with U.S. tax laws.

The summons will allow the IRS to obtain information about American taxpayers who have UBS accounts but did not file required forms detailing their taxable income.

"The order clears the way for the IRS to take the next steps against wealthy individuals who don't pay their taxes," said IRS Commissioner Doug Shulman in a written statement. "People with hidden foreign accounts can no longer rest easy."

UBS has said it is cooperating with Swiss and U.S. investigations and will disclose records involving U.S. clients who might have broken tax laws.

"As we have noted, UBS takes this matter very seriously and is working diligently with both Swiss and U.S. government authorities, consistent with Swiss law and the legal frameworks for intergovernmental cooperation and assistance," UBS said in a statement Tuesday.

U.S. taxpayers are required to report all foreign financial accounts if their total value exceeds $10,000 at any point during a given year, prosecutors said. Failure to report the accounts can result in a penalty of up to 50 percent of the amount in the accounts.

The Justice Department requested the summons after former UBS private banker Bradley Birkenfeld, 43, pleaded guilty in a Florida federal court to defrauding the IRS. Birkenfeld, who is cooperating with investigators, said in court that UBS has about $20 billion in assets in undeclared accounts for U.S. taxpayers.

Prosecutors said Birkenfeld and others helped California billionaire Igor Olenicoff hide $200 million in assets overseas. Olenicoff, who controls a real estate empire, pleaded guilty last year to tax charges and agreed to pay the IRS more than $52 million.

All the extra money helped to push consumer spending up by the largest amount in six months, but economists warned the boost would likely prove short-lived given all the other problems facing consumers at present.

The Commerce Department reported Friday that after-tax disposable incomes jumped by 5.7 percent in May, the biggest one-month gain since a 6.3 percent increase in May 1975 when Ford was president. He was fighting a recession that year with a program to mail individual taxpayers $50 checks.

This time around individual payments range from $300 to $600 with couples getting up to $1,200. In all, $48.1 billion in rebate payments were made in May and through this week, the government announced Friday, payments total $78.3 billion — three-fourths of the $106.7 billion scheduled to be paid to 130 million households. The payments are to be completed by mid-July.

A former UBS banker and an adviser from Liechtenstein have been charged with helping clients, including California real-estate billionaire Igor Olenicoff, avoid paying taxes, according to a published report.

Bradley Birkenfeld, who worked at UBS from 2001 to 2006, appeared in court Tuesday. He is alleged to have helped clients use secret bank accounts and file false tax returns, according to a report in The Wall Street Journal. See story in WSJ.com

The case could lead to other U.S. clients as Birkenfeld and Mario Staggl, who owns a trust company called New Haven Trust in Liechenstein, courted rich Americans, the newspaper reported.

The indictment against the pair doesn't mention UBS by name, referring only to a Swiss bank, according to the Journal.

Senate Republicans strongly oppose those measures, which are widely viewed as having little chance of being enacted. Even then, they would almost certainly prompt a veto by President Bush.

The 25 percent windfall profits tax would apply only to oil companies that "fail to invest in increased (production) capacity and renewable energy sources," according to a summary of the proposals released by Senate Majority Leader Harry Reid's office.

The energy proposals also seek to halt deliveries of oil into the government's Strategic Petroleum Reserve until oil prices drop to $75 a barrel.

Q: When do I get my economic stimulus payment (aka tax rebate)?

A: Some people may actually see their money as early as today. Here's the schedule, if you filed your federal tax return by the April 15 deadline and the IRS processed it by then. If you filed jointly, the Social Security number listed first will determine when you'll get your rebate. If you sign up for direct deposit on your tax return, find the last two digits of your Social Security number to determine when the tax rebate will be deposited into your account:
00 - 20, May 2
21 - 75, May 9
76 - 99, May 16

If you didn't sign up for direct deposit, expect a paper check in the mail during these dates, according to the last two digits of your Social Security number:
00 - 09, May 16
10 - 18, May 23
19 - 25, May 30
26 - 38, June 6
39 - 51, June 13
52 - 63, June 20
64 - 75, June 27
76 - 87, July 4
88 – 99, July 11

Q: Why did I get less than my friends and neighbors?

A: The economic stimulus payment is based on your 2007 income tax return. Most taxpayers qualify for the maximum payment of $600 for singles or $1,200 for married couples. Many parents also get $300 for each qualifying child, born after Dec. 31, 1990.

Here are some reasons the IRS may send you less than the maximum:

You are single and your net income tax liability is less than $600. (On Form 1040, your net income tax liability is Line 57, plus the amount on Line 52.) You are married and your net income tax liability is less than $1,200. You are single and your adjusted gross income (AGI) is more than $75,000. (On Form 1040, this is Line 37.) You are married filing a joint return and your AGI is more than $150,000. You owe back taxes. You have federal debts such as unpaid student loans or child-support obligations.

Q: I filed my return on time, but still haven't gotten my rebate. The schedule says I should have gotten it by now.

A. The IRS says the payment schedule (listed above) only applies if your return was received and the IRS finished processing your return before April 15. If you filed your return on time, but close to the April 15 deadline, the IRS may not have finished processing it before April 15. If you're expecting a regular tax refund, the IRS will send that to you first. The tax rebate will follow about a week or two later. If you're not expecting a regular tax refund, your stimulus payment should arrive a minimum of six weeks after you filed your return.

Q: I filed after April 15, and the payment date for my Social Security number has passed. When will I get my rebate?

A. A minimum of six weeks after you file your return.

Q: To which address is the rebate mailed?

A: The rebate will be sent to the last known address the IRS has on file, if you did not elect direct deposit.

Q: How do I know if I won't get a rebate?

A: You won't get a rebate in 2008 if any of the following apply: You don't file a 2007 tax return. Your net income tax liability is zero and your qualifying income is less than $3,000. To determine your qualifying income, add together your wages, net self-employment income, nontaxable combat pay, Social Security benefits, certain Railroad Retirement benefits and certain veterans' payments. You can be claimed as a dependent on someone else's return (whether or not you actually are claimed as a dependent on someone else's return). This would include a child or student who can be claimed on a parent's return. You don't have a valid Social Security number. You are a nonresident alien. You file Form 1040NR or Form 1040NR-EZ, Form 1040PR or Form 1040SS for 2007.

Q. What happens if I provided the wrong direct deposit information on my return?

A. You can call to notify the IRS, but because of the timing of the refund, it may be difficult to stop the payment. If your rebate is returned by the bank, the IRS will send you a paper check.

Q: I used Direct Deposit to split my refund between several accounts when I filed my tax return. Where will the rebate be deposited?

A: If you split your refund between several accounts, you will not get your rebate by direct deposit. The IRS will send you a paper check.

Q: What happens to my rebate if I requested a Refund Anticipation Loan (RAL) from my preparer?

A: If you use RALs or enter into any other loan or financial agreement with your tax professional, you won't get your rebate direct deposited. The IRS will send you a paper check.