Updated

The uneasy relationship between the Obama White House and the U.S. Chamber of Commerce has steadily eroded over the past several months, with the business group's opposition to health care and climate change legislation triggering an all-fronts backlash from the administration.

The administration is now trying to neutralize the Chamber by doing an end-run around the group and dealing directly with its members.

During remarks in early October, President Obama named and shamed the Chamber for opposing a consumer protection agency.

And the White House again criticized the group Tuesday, telling Fox News in an e-mail that the group's opposition to reform efforts gives the administration pause.

"We have an open door to the ideas and suggestions of the business community including the Chamber," White House spokeswoman Jen Psaki said, noting that administration "representatives" met with Chamber representatives last week. "But it does give us pause that they continue to throw millions of dollars against productive efforts under way to reform the regulatory structure, provide access to affordable health insurance for more Americans and reduce the impact of greenhouse gas emissions -- all plans essential to the continued growth and recovery of our economy."

Obama and top aides quietly have met with 50 to 60 big-time corporate CEOs over the past few months in an effort to cultivate their support on key issues -- the White House denies that it has encouraged any companies to sever ties with the Chamber.

A few companies, like Apple Inc., have left the Chamber principally due to disagreements over how to tackle climate change. Others, like Nike, have simply left the board of directors.

But Chamber executives told Fox News that since word of open warfare with the White House began to surface, membership has spiked. They warned White House Chief of Staff Rahm Emanuel not to imagine the Chamber will retreat from spending heavily in the mid-term election cycle.

"Let's not make any mistake. The United States Chamber of Commerce will be active, we will be visible and we will be very engaged in the 2010 elections. Rahm, I'm sure, well appreciates that," said R. Bruce Josten, executive vice president for the Chamber of Commerce.

The relationship wasn't always so combative.

The well-funded and deeply entrenched pro-business lobby spent heavily on GOP candidates last year. But during the transition and winter months, Chamber executives met frequently with Obama aides and supported the administration on the bank bailouts, the stimulus package and high-level nominees.

Then came the health care debate, during which the Chamber actively opposed Democratic reform plans, not long after the group had rallied opposition to White House efforts on climate change and regulatory reform.

By early October, the gloves were off.

At one White House event, Obama called out the group as he delivered remarks urging Congress to create a new consumer protection agency, describing Chamber ads on the topic as "completely false."

"The U.S. Chamber of Commerce is spending millions on an ad campaign to kill it," Obama said. "They're trying their hardest to weaken it. ... And they're very good at this, because that's how business has been done in Washington for a very long time. In fact, over the last 10 years, the Chamber of Commerce alone spent nearly half a billion dollars on lobbying -- half a billion dollars."

Analysts see risks and rewards for the White House in taking on the Chamber so directly.

"Traditionally the Chamber had a special place in Washington. It was viewed as so powerful and so mainstream that you took it on at your risk," Democratic strategist Susan Estrich said. "I think this White House has brought the Chamber down ... to the level of another trade group. And if they become another trade group, it's much easier to cross them."

One group already crossed the Chamber on Monday, when a fake press release went out declaring the group had dropped its opposition to climate change legislation.

After several news organizations briefly picked up the item, the Chamber sent out a statement declaring that the release was a hoax.

A representative from the liberal activist group The Yes Men claimed responsibility in an interview with Politico.com.

Fox News' James Rosen contributed to this report.