Candidates are touting their political independence, blaming incumbents for high gas prices and warning moderate voters of a possible liberal takeover of Congress in a current wave of advertising that is revealing some themes for the final weeks before Election Day.

Across the country in competitive House and Senate races, Democrats and Democratic-leaning groups are criticizing Republicans for receiving contributions from the oil industry and advocating oil exploration tax breaks while consumers pay more at the pump.

With the public holding the GOP-controlled Congress in low esteem, Republican are using ads to present themselves as independent-minded public servants who don’t toe the party line. And in at least one race, the National Republican Congressional Campaign is running an ad warning that a Democratic victory would lead to higher taxes, greater illegal immigration and a "cut and run" policy in Iraq.

Though the ad messages are likely to change from race to race, they showcase overarching campaign motifs that both parties and their candidates have been perfecting throughout the summer.

Party operatives and outside strategists predict pocketbook issues such as taxes and a higher minimum wage will play a dominant role in the coming advertising wave. They said ads also will seek to capitalize on national news and issues commanding attention in Congress.

That said, the NRCC has no plans to dovetail its advertising strategy to Congress’ current focus on national security topics, said Carl Forti, a campaign committee spokesman.

"Our races are local races," he said, reiterating the party’s determination not to make the election a referendum on President Bush or the Republican Party.

Still, the committee is running an ad on behalf of Rep. John Hostettler (news, bio, voting record), R-Ind., saying a Democratic victory would place Congress under the control of Democrats such as House Minority Leader Nancy Pelosi, D-Calif.

"Control of Congress is at stake in the coming election," the ad states. "Pelosi and other Democrats want to raise your taxes, cut and run in Iraq and give amnesty to illegal immigrants."

The Democratic Congressional Campaign Committee is hitting back, singling out oil industry contributions to Republican Reps. Chris Chocola in Indiana and Charles Taylor in North Carolina, and to Republican John Gard, a candidate for an open seat in Wisconsin.

In Ohio, Rep. Steve Chabot is the latest Republican to hit the air with an ad touting his independence. The ad doesn’t even mention Chabot’s party allegiance and says "he follows his heart, not the crowd."

"Steve Chabot has a reputation for going his own way when it means standing up for us," the ad says.

Similarly, a recent ad by Rep. Deborah Pryce of Ohio, a member of the party’s congressional leadership, described how she "stood up to her own party" and sought more money for stem cell research.

New ads by Democrats cite a broad range of national issues such as Iraq, health care and Social Security and portray Democratic candidates as agents of change. Republican candidates stress local concerns and controversies and present the election as choices between two candidates.

Chocola, for example, criticizes Democratic opponent Joe Donnelly in a new ad for opposing a federal energy bill that contained money for production of corn-based ethanol, an important additive in Indiana farm country. A Donnelly ad focuses on Social Security and Medicare.

The post-Labor Day ads represent the first hints of a rising wave of ads that will hit with full force in mid- to late September. The NRCC has reserved more than $47 million worth of time for ad buys in the last six weeks of the campaign; the DCCC has reserved more than $53 million.

As of the end of July, when the latest data was available, neither party had enough cash on hand to cover such an expense. But both committees continue to raise funds and, ultimately, could borrow to cover the cost.

Meanwhile, independent advocacy groups only have until midnight Thursday to run ads for or against specific candidates. A provision of a 2002 campaign finance law prohibits them from running electioneering ads within 60 days of a general election. The Federal Election Commission deadlocked 3-3 last week in an attempt to ease that rule.

Some groups, however, plan to stay within the law by running political ads that don’t mention candidates.

The Democratic-leaning Americans United for Change is airing two new ads in markets with contested races that criticize Bush and congressional Republicans for high gas prices and for rigid policies in Iraq, on education and on oil. The ads are running in Montana, Ohio and Virginia, but don’t mention any of the candidates competing in those states.

"Keep an eye on issue groups," said Evan Tracey, chief operating officer at TNSMI/Campaign Media Analysis Group, a company that tracks political advertising. "These groups really haven’t had a chance to come through a midterm election under the new campaign finance bill."