Monday night lawmakers were already gearing up, unveiling a report that alleges Apple avoided paying taxes on $44 billion in offshore, taxable income.

A Senate panel says Apple did not break the law but did find a new way to limit its tax burden — three of its subsidiaries in Ireland do not pay income taxes to any country.

( Also on POLITICO: Senate investigators: Apple hid $44B from taxes)

To deal with the nasty optics, Apple has turned to a top Washington law firm for help, O’Melveny & Myers – veterans at trying to keep big companies out of trouble, like Enron, Ford and Goldman Sachs.

Firms like O’Melveny & Myers work closely with committee investigators to track down what CEOs can expect to face. And they try to limit the scope of the investigation before the hearing even takes place.

Apple has also sent its own hired guns to Capitol Hill for recon duty. Their mission: find out the planned line of questioning and expose any surprises senators plan to air.

( Also on POLITICO: Opinion: End the political circus on tax reform)

Meanwhile, Cook and two other top execs are doing their homework in Apple’s Washington office, which has become ground zero for the company’s preparations.

It all shows just how seriously Apple is taking the threat of a public spectacle that can damage a brand with shareholders and the public — even if senators never get around to new regulation.

Corporate lobbyists, investigative lawyers and consultants say extensive preparation can make the difference from getting through the process largely unscathed to creating a bigger PR mess and potentially putting a company’s bottom line in jeopardy.

“The goal is to make the hearing prep even more difficult than the hearing is going to be. It sort of like boot camp,” said Kirkland & Ellis’ Brian Benczkowski, who prepped senior witnesses at the Justice Department during the Bush administration and has counseled senior execs at companies like Fisker Automotive in the private sector.

( PHOTOS: Politicians and their iToys)

In Apple’s case, Sen. Carl Levin (D-Mich.) is expected to hit the iPhone maker hard for keeping money overseas – allegedly to avoid paying steeper U.S. taxes. Apple held $102.3 billion cash offshore as of March 30,according to a Securities and Exchange Commission filing. That’s a 24 percent increase from Sept. 30.

Levin has been a vocal advocate for tax reform of offshore tax havens and has particularly focused on tech companies, calling Hewlett-Packard and Microsoft before thepanel last year over the same issue.

On Monday, his panel released a 40-page bipartisan report that grabbed headlines by outlining that Apple sheltered $44 billion from taxes – and how it did so.

Apple did not respond to a request for comment, but it did release its testimony Monday, another sign of playing offense.

In an interview with POLITICO last week, Cook defended Apple’s business practices.

“I can tell you unequivocally Apple does not funnel its domestic profits overseas. We didn’t do that. We pay taxes on all the products we sell in the U.S., and we pay every dollar that we owe. And so I’d like to be really clear on that,” Cook said.

Former Sen. Norm Coleman, who previously chaired the same investigative panel Apple is appearing before, said companies could be called to testify for many reasons.

He said in this instance, Levin could be using Apple to highlight an example of where the law is the problem.

“Folks in many cases are working with the IRS, they are following the law doing what the law dictates,” Coleman said. “If Chairman Levin goes down that route, the problem isn’t necessarily the companies, this is what the IRS dictates and folks are following them. It’s not a hostile witness.”

The companies opening statement is also key because it allows executives to lay out the case from their perspective. Apple’s Tim Cook made its case in a several-minute long introduction in a POLITICO interview last week where he outlined the tech company’s tax bill, nearly $6 billion in fiscal year 2012 and an estimated $7 billion in 2013. He also discussed the company’s growing U.S. manufacturing footprint and highlighted that he would produce tax reform policy the company would support.

For executives, a large part of the process is making them understand how lawmakers might take an argumentative tone and to not take the bait. Often executives and consultants engage in a mock back and forth during prep with consultants trying to channel lawmakers’ questioning style.

In what can at times be hours-long testimony, the prep can help prepare execs not used to being on the hot seat, getting asked the same questions over and over again.

For Apple’s Cook, it will be his first time facing Levin and other senators at the dais with the cameras rolling.

Wiley Rein’s Robert Walker said many business leaders aren’t used to appearing before a congressional hearing.

“It is a unique environment. It is in part real fact-finding. It is in part political… It can be distracting,” Walker said.

Stanley Brand, a veteran legal counsel in congressional investigations, said he prepares clients as he would if they were facing a legal deposition.

“The risk and the tendency is to get sloppy and get relaxed and getting into a conversation. In my view you shouldn’t be doing that in that hearing. You are under oath,” said Brand, who has worked with Lehman Brothers, Major League Baseball and Arthur Andersen. “These committees have referred people or entities to the DOJ and you have collateral exposure because litigants, shareholder groups, and competitors are watching.”