Reuters

Republican presidential candidate Mitt Romney

Washington - The campaign of Republican presidential candidate Mitt Romney on Thursday launched a fierce attack on Newt Gingrich, who shot to double-digit leads over Romney in opinion polls of several states.

Romney's campaign unleashed two respected conservative Republicans - former White House chief of staff John Sununu and former Senator Jim Talent - to question Gingrich's ability to take on President Barack Obama.

Talent, a congressman in the 1990s when Gingrich was Speaker of the US House of Representatives, shot the strongest salvo by saying a Gingrich nomination would hand Obama the election next year.

“If the nominee is Newt Gingrich then the election is going to be about the Republican nominee - which is exactly what the Democrats want,” Talent said on a conference call with reporters.

He said if Romney was the nominee the race would not be focused on him but on Obama's record and the Republican would have a good chance of winning.

“If they can make it about the Republican nominee then the president is going to win and that's exactly why they're pursuing the strategy they're pursuing now - attacking Mitt Romney in advertisements because they're hoping Governor Romney is not going to be the nominee,” Talent said.

A series of new polls showed Gingrich has been gaining ground and jumped to double-digit leads over former Massachusetts Governor Romney in several states including some of the first voting states for the Republican primary.

A poll released on Thursday by Quinnipiac University showed that in head-to-head matchups in the key states of Florida, Ohio and Pennsylvania, Republican voters prefer Gingrich as the nominee to compete against Obama in the 2012 election over Romney by margins of 18 to 27 percentage points.

In a general election, the poll found that Obama would beat Gingrich in Florida and Pennsylvania but would lose to him in Ohio. It said Romney would beat Obama in Florida and Ohio but not in Pennsylvania.

A separate CNN/Time poll showed that Gingrich would beat Romney in Iowa, Florida and South Carolina - three of the four first states to hold nominating contests early next year - by double digits. Romney was leading Gingrich by 13 percentage points in New Hampshire, the CNN/Time poll said.

The CNN/Time poll showed that about half of those surveyed said they might still change their minds.

“I want someone with fire in his belly,” said Sue Mersereau of West Des Moines, who is deciding between Romney and Gingrich. “I just want somebody who can beat Obama.”

“Mitt's got to do something. He needs to get out there and show he can take Obama down,” she said. “I know Newt can. I don't know that Mitt can.”

“Former House Speaker Newt Gingrich is no longer just the flavour of the month,” said Peter Brown, assistant director of the Quinnipiac University Polling Institute.

“Gingrich's surge in the GOP (Republican) race is accompanied by a better showing among independent voters in a general election race against President Obama, although he still has a ways to go.”

The Romney campaign shrugged off the polls and said they would focus on differences between Romney and Gingrich.

“There is a lot of game left to be played,” said spokeswoman Gail Gitcho.

Sununu, who was also former governor of New Hampshire, said Gingrich would not make a good commander-in-chief because of his “irrational behaviour”.

“The off-the-cuff comment that Gingrich throws out on occasion is a reflection of the off-the-cuff thinking that he goes through to deal with issues. And that is not what you want in a commander in chief,” said Sununu.

The Quinnipiac poll had a margin of error of plus or minus 2.6 to 2.8 percent for the questions relating to a national election. Questions posed to just Republicans had a margin of error of plus or minus 4.1 to 4.3 percent. - Reuters