CHICAGO - A combative Gov. Rod Blagojevich served notice Friday that he has no intention of quitting over his corruption arrest, declaring: "I will fight. I will fight. I will fight until I take my last breath. I have done nothing wrong."

The forceful three-minute speech marked the first time the former amateur boxer directly addressed the allegations since his arrest 10 days earlier. With it, he made it clear that removing him could be uglier and more drawn-out that anyone imagined just a week ago, when the governor's career appeared to be in its final hours and nearly the entire political establishment seemed to be holding a death watch.

"I'm not going to quit a job the people hired me to do because of false accusations and a political lynch mob," a composed and deliberate-sounding Blagojevich said at his downtown Chicago office building. He took no questions from reporters and immediately left the room after wishing his listeners, "Merry Christmas, happy holidays."

The 52-year-old Democrat is charged with scheming to sell president-elect Barack Obama's vacant Senate seat for big campaign contributions or a lucrative job for himself. Prosecutors built their case on Blagojevich's wiretapped conversations.

"I'm here to tell you right off the bat that I am not guilty of any criminal wrongdoing, that I intend to stay on the job, and I will fight this thing every step of the way," Blagojevich said.

Acknowledging his political isolation, he recited the opening lines of the stirring poem "If" by Rudyard Kipling, a writer Winston Churchill was also fond of quoting: "If you can keep your head when all about you are losing theirs and blaming it on you ..."

What he hopes to accomplish by staying in office appears unclear. Blagojevich appears to have no political support, the Illinois House having voted 113-0 last week to assemble an impeachment committee, and his ability to govern has been crippled.

Republican state Senator Dale Righter said that if Blagojevich manages to escape impeachment, his governing will be limited to signing legislation, directing his agencies and other "housekeeping stuff." Blagojevich will not be able to work with legislators or energize the public to support his ideas, Righter said.

"Is this governor finished as a leader? I don't think there's any question about that," he said. "I don't think the instrument has yet been invented that can measure how little credibility he has."

After the speech, disappointed Republicans argued that if Blagojevich cannot be dislodged right away, he should at least be disarmed. They called on the Democrats in the legislature to hold a special election to fill the Senate seat, stripping Blagojevich of the power to make the appointment.

"Anything short of resignation today from the governor was unacceptable," said Illinois Republican chairman Andy McKenna.

Democratic Lt.-Gov. Pat Quinn pleaded with Blagojevich to step aside under a constitutional provision that allows him to keep his title but give his duties to an acting governor -- which, under the rules of succession, would be Quinn.

"Our state cannot wait while the chief executive battles in the court of law while we have so many issues affecting safety and welfare of the state of Illinois," Quinn said.

Even before the speech, Blagojevich's lawyer, Ed Genson, a hard-charging Chicago criminal defence lawyer, had made it plain the governor would not go down without a fight.

Genson challenged the Illinois House impeachment committee at every turn this week, arguing that the wiretaps were illegal, accusing some of the panel members of having already made up their mind, and complaining that Illinois law does not spell out the grounds for impeachment or what evidence should be considered.

"He'll worry about the criminal part, the governor will continue to govern," said another Blagojevich lawyer, Sam Adam Jr.

Other lawyers said Genson is on the right track in contesting the legality of the FBI wiretaps, though they warned that few such challenges succeed.

"But the more noise you make about it, the more chance you have of getting it suppressed," said professor Leonard L. Cavise of DePaul University College of Law. "This is going to be a big deal."

The impeachment panel wants federal prosecutors to release details of their probe of Blagojevich, including copies of the taped conversations, and give the legislature some guidance on who can be called as a witness without compromising the federal case.

Federal prosecutors' case could be undermined if Illinois legislators compel certain witnesses to testify. Oliver North's conviction in the Iran-contra scandal of the 1980s was thrown out after the courts concluded that prosecutors had improperly used testimony North gave to Congress under a grant of immunity.

Blagojevich's uncompromising stand came as little surprise to those who know him.

For years the former boxer has cultivated an image as a fighter -- dating back to his youth, when he trained for the Chicago Golden Gloves. During his first campaign for governor in 2002, Blagojevich and his aides would sum up each day's success in boxing terms: 10-10 for a draw, 10-9 a win, 10-8 a decisive win, a knockdown, and so on.

Once in office, he earned a reputation for publicly sparring with everyone from his Chicago alderman father-in-law to the powerful Democratic House speaker.

"Now I know there are some powerful forces arrayed against me," Blagojevich said Friday. "It's kind of lonely right now. But I have on my side the most powerful ally there is, and it's the truth. And besides, I have the personal knowledge that I have not done anything wrong."