WASHINGTON, Sept 13 (AFP) - US Democratic presidential challenger John Kerry went on the offensive against President George W. Bush over a 10-year-old ban on assault weapons that ends Monday.
Kerry, lagging behind Bush in most opinion polls, accused the Republican president of making it easier for killers to purchase AK-47s and other weapons that will become legal again from midnight.
Bush, in turn, sought to focus attention ahead of the November 2 election on the cost of his rival's health care and tax plans.
The president has been widely accused of giving in to the powerful gun lobby over the lapse of the assault weapon ban. From midnight weapons such as AK-47s, Uzis and other military-style weapons can be legally sold in most states.
Bush had said he would support an extension of the ban if Congress passed legislation. But the Republican leadership in Congress rejected the ban and Bush did not call on the Senate or House to take action.
Kerry blasted the president in a Washington speech as he accepted the backing of the National Association of Police Organisations.
"When it became time to fight, when it became time to lead, when it became time to stand up and ask America to do what was right, George Bush's powerful friends in the gun lobby asked him to look the other way, and he couldn't resist, and he said, 'sure'.
"And so tomorrow, for the first time in 10 years, when a killer walks into a gun shop, when a terrorist goes to a gun show somewhere in America, when they want to purchase an AK-47 or some other military assault weapon, they're going to hear one word: 'Sure'."
Kerry went on: "George Bush chose to make the job of terrorists easier and make the job of America's police officers harder, and that's just plain wrong."
The Massachusetts senator has stepped up his attacks on the president since opinion polls after the Republican convention showed Bush with a lead of up to 11 percentage points over Kerry.
Americans have consistently rated Bush as the better candidate on national security.
Bush campaigned in Michigan and told voters in the battleground state that Kerry would raise their taxes and put "bureaucrats" in charge of health care.
Bush, in a rare shift in focus from national security, targeted Kerry's ambitious plan to help families facing growing medical costs and the tens of millions of people without health insurance.
"I'm running against a fellow who has got a massive, complicated blueprint to have our government take over the decision-making in health care," the president told supporters.
"His plan, if you listen carefully to what he says, would have bureaucrats be the decision makers."
Bush cited a conservative think-tank's estimate that the Democrat's health care proposal would cost 1.5 trillion dollars over 10 years, and warned: "He can't pay for it unless he raises your taxes."
Kerry, who sharply disputes that cost estimate, has said he would pay for his domestic policies by repealing part of Bush's huge tax cuts that benefit the biggest US earners.
"You can't tax the rich enough," to pay for the plan, the president countered. "The rich hire accountants and lawyers for a reason. And you get stuck with the bill.
With polls showing he lags behind Kerry on domestic issues like health care, Bush touted a series of modest initiatives as well as controversial legislation extending the Medicare government administered health care for the elderly to cover prescription drugs.