UPDATE 2-Top Republican Raises Heat on Obama in Keystone Letter

* Republicans attack Obama's energy policies

* Rising gasoline prices could affect presidential race (Adds Zogby poll, fresh Carney quote)

By Alister Bull

WASHINGTON, Feb 28 (Reuters) - Republicans turned up the heat on President Barack Obama's energy policies on Tuesday, hammering an election-year issue that they view as his weak spot amid rising gasoline prices.

House of Representatives Speaker John Boehner, the top Republican in Congress, wrote to Obama to urge him to approve a controversial oil pipeline and fulfill a promise of an "all of the above" approach to ease dependence on foreign oil.

Republicans have intensified their attacks on the Democratic president's energy policies in recent days, blaming them for higher pump prices that could hurt Obama's re-election prospects in the Nov. 6 face-off against the eventual Republican presidential nominee.

"To provide greater energy security, I would urge you to change course and expeditiously approve the pipeline permit as soon as the application has been filed," Boehner said in a letter to Obama, a copy of which was seen by Reuters.

However, the White House said it was wrong to suggest that TranCanada Corp's proposed Keystone XL crude oil pipeline could quickly help bring down prices at the pump.

"That's the kind of empty promise that politicians make when we face hikes in the global price of oil that is really dishonest," said White House press secretary Jay Carney.

Gas prices rose 7 cents in the week to Feb. 24 to a national average of $3.60 a gallon and in some parts of the country are much higher, creating a drag on household budgets that could sap an economic recovery that appears to be underway.

A poll published by IBOPE Zogby International found 54 percent of those surveyed had cut back on driving as a result of high gas prices and almost half had trimmed spending. The poll found people were somewhat more inclined to blame Congress for the increase in fuel costs than Obama, but the public's anger still represents a potent campaign weapon.

DEMOCRATS' CONCERN

Steny Hoyer, the No. 2 Democrat in the House, said he was "concerned about the impact it has on the administration," acknowledging a threat to Obama's re-election prospects that has been aggressively seized by his opponents.

Republican candidates vying to face Obama in November have vowed to do a better job of holding gas prices down, and Senate Minority Leader Mitch McConnell, accused the White House of trying to deflect blame for increased pain at the pump.

"Make no mistake: the rising price of gasoline isn't simply the result of forces we can't control. It is, to a large extent, the result of a vision that this president laid out even before he was elected to office," McConnell said in a Senate speech.

The White House has emphasized record levels of domestic oil production. But Boehner argued that production flowed from policies put in place by Republican President George W. Bush, and called on Obama to back legislation to expand domestic exploration.

Obama last month rejected the Keystone XL pipeline, which was to run through environmentally sensitive areas of Nebraska from the U.S.-Canadian border.

On Monday, the White House said it welcomed a fresh proposal by TranCanada to build a southern leg of the pipeline and refile an application for the northern part of the route.

That may help blunt the Republican attacks over the pipeline, but Boehner said the country could not afford to take its time.

"The current turmoil in the Middle East and its effect on gas prices reminds us how dangerous it is to rely so much on that region for our energy supply," he said. "We can't wait for this project to get started." (Reporting By Alister Bull; Editing by Paul Simao and Christopher Wilson)