(CNN) -- Military supporters descended on Berkeley early Tuesday, demanding the famously liberal California college town rescind its vote that says Marine recruiters are "not welcome in this city."

Military supporters and anti-war demonstrators began gathering in Berkeley early Tuesday. more photos »

The pro-military demonstrators were met by anti-war protesters who had camped out overnight, setting the stage for a dramatic showdown late in the day when the City Council is to discuss whether to revoke its previous vote.

"Their treasonous action, especially at this time of war right now, is not acceptable," said Mary Pearson, a spokeswoman for the group Move America Forward.

"It's very, very important for everyone to stand united ... to give our Marines and all of our military the greatest respect and honor that they deserve."

Before the sun was even up, about 300 demonstrators -- both pro-military and anti-war -- were already standing toe-to-toe in downtown. Many traded jeers and sneers.

"Code Pink doesn't stand for us," one sign said, held by a man in military fatigues. Signs held by anti-war activists read, "End the War" and "Bring the troops home now."

The City Council is to meet at 7 p.m. PT on whether to take back its previous measure urging the Marine recruiters to leave town.

"If recruiters choose to stay, they do so as uninvited and unwelcome intruders," the measure says.

It went on to say the council applauds residents and organizations that "volunteer to impede, passively or actively, by nonviolent means, the work of any military recruiting office located in the City of Berkeley."

Ever since the council measure, protesters with the anti-war group Code Pink have camped outside the Marine recruiting office on Shattuck Avenue, singing peace songs and chanting slogans for an end to the Iraq war. See photos of Code Pink protesters outside Marine office »

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Republican lawmakers in Washington fired back last week, threatening to recall more than $2 million of federal funding to the city as well as money designated for the University of California-Berkeley, the campus that became a bastion of liberalism during the Vietnam War.

The Marine Corps has said it has no plans to move its office, which is located about a block from the college campus.

Whether the City Council reverses course remains to be seen.

Max Anderson, a Vietnam war veteran who serves on the council, said he fully supports the measure to get Marine recruiters out of town -- despite receiving more than 8,000 e-mails, most of them harsh in tone, on the matter.

"If the aim was to shut us down, get us to back up, get us to eat our words, get us to retreat from our position with the war, they can forget that," he told CNN Monday.

He said he was recruited by Marines after he graduated from high school in 1963 and was promised that he and his friends would serve together. But once they enlisted, he said, they were separated and shipped off to Vietnam.

"We're not against the Marines per se," he said. "We're against this war. We're against the mechanisms that support this war and send our young people over there."

Kriss Worthington, a progressive Berkeley activist and council member for 11 years, believes the council overreached.

"The inflammatory language in the City Council item is really outrageous -- not just to right-wing people, but to mainstream liberal people and even to some peace activists who have said they're insulted that the city would have such language," Worthington said.

He said Berkeley owes an apology to the military and to the peace movement "for having such embarrassing language allegedly trying to promote peace."

"When you make a colossal blunder, you can't just sort of ignore the mistake and go about your way. You have to do something to fix it," Worthington said. E-mail to a friend

CNN's Chuck Afflerbach contributed to this report.

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