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An Obama-era regulation that tightened gun checks on mentally ill buyers has been blocked by the US Senate and could be signed into law by the White House.

The law stopped people who receive disability benefits from buying guns, affecting an estimated 75,000 people.

But Republicans, who control the Senate, argued it stigmatised the disabled and voted it down 57 to 43.

President Donald Trump is set to approve revoking the rule, his first action on guns since taking power.

It passed the House of Representatives last week.

After the Sandy Hook shooting tragedy which killed 20 children and six adults in 2012, President Barack Obama introduced a measure that required the Social Security Administration to report information on people with mental illness to the FBI.

Adam Lanza, the 20-year-old man who went on a shooting rampage at the elementary school, suffered from a variety of impairments including Asperger's syndrome and obsessive-compulsive disorder.

In an interview with the BBC, Mr Obama said his inability to pass "meaningful" gun legislation was his biggest frustration.

Media playback is unsupported on your device Media caption Texas women and their firearms

Republican Senator Chuck Grassley, who led the repeal effort, said the regulation "unfairly stigmatises" people with mental illness and infringed on their constitutional right to bear arms.

Mr Grassley used eating and sleep disorders as examples that could fall under the regulation requiring a more extensive background check.

The regulation, however, does not stipulate that any person with a disability would be affected.

Rather, it focuses on people who are unable to deal with their own finances and require a trustee to administer them.

"If a specific individual is likely to be violent due to the nature of their mental illness, then the government should have to prove it," Mr Grassley said.

Media playback is unsupported on your device Media caption Mr Obama told the BBC that gun control was his biggest frustration

But Mr Grassley was not alone in criticising the Obama era regulation.

The American Civil Liberties Union and more than a dozen advocacy groups for the disabled opposed the rule, arguing it painted people with mental illness with too broad a brush.

Democratic lawmakers also weighed in, criticising Republicans for making it easier for people with mental illness to obtain a firearm.

"I don't know why we think that somebody who literally can't manage their own financial affairs could be a responsible gun owner," Democratic Senator Chris Murphy said.

"I hope something truly awful doesn't happen because of this."

Dan Gross, president of the Brady Campaign to Prevent Gun Violence, also condemned the resolution.

"Make no mistake, this vote was really about deepening the gun industry's customer pool, at the expense of those in danger of hurting themselves or others," he said.