Republican Mitt Romney has angrily blasted what he called “false” attacks on his time at Bain Capital, but did not cede to demands to release more tax returns that have dogged his White House bid.

On Friday, President Barack Obama called on Romney to answer questions about his tenure at Bain after a Boston Globe report cited government records appearing to show Romney was in control of the firm for three years beyond 1999, when he says he stepped down.

The date could be important, as Bain Capital is alleged to have invested in firms that moved workers overseas after that year and Obama supporters are attempting to paint the Republican White House hopeful as a destroyer of jobs.

But after the Democratic incumbent himself said Romney owed the American people answers ahead of the November 6 vote, the former Massachusetts governor sounded off in five interviews to major US television networks.

He blasted the Obama camp’s claims as “false, misleading, wrong-headed.”

The protracted row over Bain and whether Romney or Obama is more responsible for sending US jobs offshore has emerged as a central issue in the campaign. Each camp is using highly personal attacks as they try to undermine voters’ trust in the other side.

Obama said close scrutiny of Romney’s overall record was merited because his opponent was using his business background and ability to become “Mr Fix-It on the economy,” as “his main calling card.”

The Obama campaign has launched a blitz of TV ads in Florida, Ohio and other swing states, in which Romney is portrayed as a corporate raider who enriched himself by shipping American jobs overseas.

Obama allies have also run ads showing laid-off blue-collar, arguing that Bain takeover deals had cost them their jobs and devastated their communities.

Romney has played up his experience in the private sector, arguing it makes him qualified to put more Americans back to work.

The Republican, who has released only his 2010 tax returns and an estimate for 2011, said he had no plans to release more years worth of data, despite Democratic pressure to do so. But Romney said he would release the 2011 returns “as soon as the accountants have that ready.”

Romney’s wealth, estimated to be around $250 million, has repeatedly surfaced as an issue during the campaign as Obama tries to paint his rival as out of touch with ordinary Americans.

The Republican’s campaign has in turn criticized Obama for automatic cuts in the military budget that are due to take effect in early 2013 after Congress failed to agree on how to reduce the deficit last fall.

Before the media barrage over Bain, Obama went on the offensive in Virginia, hoping the key swing state will vote in his favor as it did in 2008.

Four months before Americans head to the polls, Obama appealed to Congress to let tax cuts for the wealthiest Americans — implemented by his Republican predecessor George W. Bush — expire, while extending those breaks for people making less than $250,000 per year.

He repeated the appeal in his radio address Saturday, calling on Congress to approve an extension of tax cuts for most Americans, but not the top income earners.

But Republicans argued that Obama’s plan will result in a massive tax increase on nearly one million small businesses.

Obama won Virginia in 2008, a first for a Democratic White House candidate since Lyndon Johnson in 1964.

His tour through rural and urban Virginia follows visits to other key battlegrounds Ohio, Pennsylvania and Iowa. Obama is scheduled to ramp up his campaigning next week, traveling to Ohio, Texas and Florida over four days.