Apple CEO Tim Cook is appearing before Congress tomorrow to talk about the company's taxes and offshore profits.

It looks like it's going to be a showdown in D.C. between Apple and Senators who think it's conducting shady business to avoid paying taxes.

Senators Carl Levin and John McCain put out a statement saying Apple has subsidiaries in Ireland that it funnels profits through, thus allowing it to avoid paying taxes.

Apple admits that it has a subsidiary in Ireland, but says it's completely legal. It also says it doesn't use tax gimmicks.

Sen. Levin disagrees with Apple, saying:

"Apple wasn’t satisfied with shifting its profits to a low-tax offshore tax haven ... Apple sought the Holy Grail of tax avoidance. It has created offshore entities holding tens of billions of dollars, while claiming to be tax resident nowhere. We intend to highlight that gimmick and other Apple offshore tax avoidance tactics so that American working families who pay their share of taxes understand how offshore tax loopholes raise their tax burden, add to the federal deficit and ought to be closed."

Here is the memorandum from Levin and McCain:

Senate on Apple