WASHINGTON (Reuters) - Democratic congressman John Lewis, a veteran civil rights leader, accused Republican John McCain and his running mate Sarah Palin on Saturday of “sowing the seeds of hatred and division” and said it reminded him of the segregationist era of Alabama Gov. George Wallace.

McCain, trailing Democratic presidential candidate Barack Obama in the polls in an increasingly tense campaign, quickly hit back, branding Lewis’s remarks “shocking and beyond the pale” and calling on Obama to immediately repudiate them.

The Obama campaign said while Lewis was right to condemn “hateful rhetoric” the Illinois senator did not believe McCain or his policy criticism were comparable to Wallace or his segregationist policies as governor of Alabama in the 1960s.

The issue of race has mostly been an undercurrent in the presidential contest between McCain and Obama, who would be America’s first black president, and it remains unknown how much of a factor it will play in the Nov. 4 vote.

Lewis’s comments, posted on his re-election website, follow widely reported outbursts of anger against Obama at McCain campaign events. McCain on Friday urged his supporters to be respectful of his Democratic rival.

“I am deeply disturbed by the negative tone of the McCain-Palin campaign,” said Lewis, an Obama supporter, civil rights icon and Georgia Democrat in the U.S. House of Representatives.

“What I am seeing today reminds me too much of another destructive period in American history. Sen. McCain and Gov. Palin are sowing the seeds of hatred and division, and there is no need for this hostility in our political discourse,” he said.

Noting that Wallace, a divisive political figure in his day, had also run for president, Lewis said, “He created the climate and the conditions that encouraged vicious attacks against innocent Americans who were simply trying to exercise their constitutional rights.”

“Sen. McCain and Governor Palin are playing with fire, and if they are not careful, that fire will consume us all,” Lewis said.

MCCAIN: ‘BASELESS ATTACK’

In a strongly worded rebuke, McCain said: “The notion that legitimate criticism of Sen. Obama’s record and positions could be compared to Gov. George Wallace, his segregationist policies and the violence he provoked is unacceptable and has no place in this campaign.”

“I am saddened that John Lewis, a man I’ve always admired, would make such a brazen and baseless attack on my character and the character of the thousands of hardworking Americans who come to our events to cheer for the kind of reform that will put America on the right track,” McCain added.

Obama spokesman Bill Burton dismissed the Wallace comparison but said Lewis “was right to condemn some of the hateful rhetoric that John McCain himself personally rebuked just last night, as well as the baseless and profoundly irresponsible charges from his own running mate that the Democratic nominee for president of the United States ‘pals around with terrorists.”’

McCain and Palin have both raised questions about Obama’s association with former 1960s radical William Ayers.