Updated: 8:27 p.m.

Rep. Zack Space (D) is “in an extremely vulnerable position” in Ohio’s 18th district, according to internal polling released Monday afternoon by the National Republican Congressional Committee.

The survey, conducted by the Republican polling firm On Message Inc., shows Space in a statistical dead heat with his challenger, state Sen. Bob Gibbs. Each candidate earned 43 percent in the survey of 400 likely voters taken Tuesday and Wednesday.

“Bob Gibbs is generating momentum across eastern Ohio. I think this shows that Zack Space’s loyal support for Nancy Pelosi and her job-killing agenda is costing him,” NRCC spokesman Tory Mazzola said. “As a result, we’ve seen this race move from an uphill fight to a real tossup.”

Asked whether they think Space has earned another term, 48 percent of respondents said no, compared with 38 percent who said yes and 15 percent who said they didn’t know.

Additionally, 62 percent said they opposed President Barack Obama’s effort to cap carbon emissions. Space voted for a global climate change bill that called for a cap-and-trade system to reduce greenhouse gases.

Space also voted in favor of the House version of the health care overhaul bill, but then voted against the Senate-passed version that was signed into law. The health care measure, Obama’s signature issue, is deeply unpopular in the district, the poll found.

The Space campaign questioned the validity of the GOP poll, saying it doesn’t match its own internal numbers.

“It just seems like they’re bringing the silly season in early. Usually they wait until October for something like this,” Space spokesman Andrew Ricci said. “It doesn’t square with what we know. And we’re not going to be head faked into releasing anything on our side.”

On June 30, Space held a massive fundraising advantage over Gibbs — $1.27 million compared with nearly $210,000 — but the On Message polling memo suggested the financial disparity won’t be a problem.

“The voters are looking to send a clear message and place a check and balance to the Obama-Pelosi agenda,” the pollster wrote in a memo. “Bob Gibbs is likely to win this race even if he is significantly outspent. In fact, Gibbs is likely to win even if he is outspent two or three to one.”