Opponents of changes to Cambridge’s sign law, voted in Monday, aren’t giving up.

Instead, they’re gathering signatures for a referendum question to overturn parts of the law that “allow Cambridge to be ‘corporatized’ by a proliferation of large illuminated signs atop the City’s tallest buildings,” said Karen Schwartzman, of Polaris Public Relations and creator of opposition website saveourskyline.org, in a press release today.

“It’s ironic, given the City’s long standing efforts to eliminate unsightly billboards, that the Council has chosen to dramatically increase corporate advertising in Cambridge,”she said. “Turning our skyline over to big out-of-state corporations is bad enough, but the city isn’t even charging for it. It’s just a giveaway!”

Councillors and others who back the changes reject the allegations, saying the changes actually toughen city law. They believe Schwartzman is the cause of much misinformation about the changes that has appeared in e-mails, letters and in public testimony at meetings and six public hearings on the topic.

Her work is funded by Intersystems, a venerable Cambridge health care software firm that shares 1 Memorial Drive — uncomfortably — with Microsoft offices and believes the Redmond, Wash., software and Internet giant is behind the sign ordinance.

From the press release:

The new provisions in the zoning law, known by many people as the “Microsoft Amendment,” emanate from that company’s interest in erecting a corporate sign atop 1 Memorial Drive, the tallest commercial building along the Charles River. Prior to the passage of this amendment, Cambridge signage regulations were as restrictive as those in abutting cities and towns. Anyone seeking to install a sign that exceeded these limits had to apply for a zoning variance and had to meet a hardship test to justify a departure from the zoning laws — a test that most observers thought Microsoft would have difficulty meeting. The amendment passed this week clears a path for Microsoft to erect a sign that will “brand” the Cambridge riverfront, visible to anyone looking across the Charles from Beacon Hill or Back Bay or entering the city over the Longfellow Bridge. Further, because the newly weakened zoning provisions are not limited to Microsoft, they open the door to a proliferation of new high-profile signs.

The City Council voted the law in 6-3 after lengthy and bitter debate. Proponents say the changes merely make the approval of signs for large business buildings less subjective and more modern, but among those voting no was Sam Seidel — leader of the Ordinance Committee that oversaw three hearings on the matter — because, he said, he objected to the commercialization of our culture.

Schwartzman seized on this. “The council’s willingness to let corporate interests dictate public policy sets a dangerous precedent,” she said, citing Seidel. “It’s time for a public debate about ‘corporatizing’ Cambridge.”

The complete press release is here in PDF form.