Romney and Obama campaigns trade ‘L-word’ as U.S. election race heats up

'Liar' is Thursday's word on the U.S. presidential election campaign.

The 'L' word is used against Barack Obama in a TV ad released Thursday by the Mitt Romney campaign.

Meanwhile, the Obama campaign referred to Romney's "big Bain lie" following a hard-hitting Boston Globe investigation published today.

"Mitt Romney stayed at Bain three years longer than he stated," reads the Boston Globe headline.

Mr. Romney has said he left Bain Capital in 1999, but the Globe cites government documents that show the former Massachusetts governor still listed as CEO for another three years.

"The timing of Romney's departure from Bain is a key point of contention because he has said his resignation in February 1999 meant he was not responsible for Bain Capital companies that went bankrupt or laid off workers after that date," writes the Boston Globe.

The Romney campaign says the Boston Globe report is not accurate -- but that didn't stop the Obama campaign.

"Romney hid the fact that he left Bain 3 years later than he claimed to avoid responsibility for outsourcing, etc," tweeted deputy campaign manager Stephanie Cutter.

"Based on Globe report, either Bain filed false SEC docs about Mitt's status, or [the] campaign [is] making false statements now," tweeted top Obama adviser David Axelrod.

Mr. Romney's tenure at Bain Capital has been a focus of reporters and the Obama campaign and it continues to dog the Republican presidential nominee.

On Thursday the Romney campaign counter-punched with a press release titled, "The Obama Campaign's Top Ten Lies & Exaggerations" and a TV ad refuting claims that Mr. Romney was responsible for shipping American jobs overseas.

"When a president doesn't tell the truth, how can we trust him to lead?" asks the narrator in the TV ad 'No Evidence.' The ad goes on to describe Mr. Obama's attacks against Mr. Romney's Bain Capital tenure as "dishonest."

Unusually, the L-word is dropped in reference to his one-time rival: "Candidate Obama lied about Hillary Clinton" – referring to a bitter back-and-forth between the two Democratic party candidates in 2008.