THREATS of physical violence made by supporters of Donald Trump against the Aberdeen campaigner behind the petition to keep the far-right billionaire out of the UK are being investigated by Police Scotland.

Suzanne Kelly, a 54-year-old New Yorker who has made her home in the north east of Scotland, has complained to police about an email warning her "never set foot outside the UK again, at least not where we can get our hands on her" and suggesting that she could "end up picking cotton" - a reference to slavery.

Kelly started a petition calling on the UK government to bar Trump, the front-runner to be the Republican Party’s candidate for US president, from entering the UK. It has been signed by over 573,000 people, and is due to be debated by the UK parliament tomorrow.

Last week Kelly went on The O’Reilly Factor, a widely-watched Fox News talk show hosted by the tough-talking hard right pundit, Bill O’Reilly. “He didn’t eviscerate me, which was good,” Kelly said.

“He’s a staunch conservative showman who got more than a bit of an aggressive twist to him. Clearly O’Reilly and Trump have a bit of bromance going on.”

For the four minutes she was on air Kelly was allowed to speak for just 1 minute and 15 seconds, with O’Reilly talking for the remaining 2 minutes 45 seconds. It looked like more of a harangue than an interview.

While insisting that he didn’t agree with all of Trump’s comments, O’Reilly highlighted problems allegedly caused by Mexican immigrants in the US and Muslim refugees in Europe. He said it was wrong of Kelly to accuse Trump of “hate speech” and try to have him stopped from entering the UK. Trump has called for Muslims to be banned from the US, and referred to Mexicans as rapists and drug dealers.

Kelly defended her position, pointing out that in two cases reported in the US, perpetrators of violence had quoted Trump in defence of their actions. She pointed out that Trump had called for the families of terrorists to be “taken out”.

She told the Sunday Herald that she was worried about the appeal to America’s “baser instincts”. Americans, she said, tended to like “the get-in-there–and-attack” O’Reilly style.

She added: “It’s not a calm, logical, lucid way of analysing issues. It’s just somebody force-feeding a conservative agenda down your throat.”

Kelly, who has dual UK and US citizenship, has lived in Aberdeen since 2003. She works for a company in the energy sector and writes for Aberdeen Voice, a campaigning online news platform set up to challenge the city’s mainstream media.

She has campaigned against Trump’s controversial golf resort at Menie on the Aberdeenshire coast, and backed a series of complaints made by local residents. She is very critical of the local media for failing to scrutinise Trump’s activities.

Since she launched the petition against Trump on December 8, Kelly has been much in demand by the media across the world. She has done more than 25 interviews, turned down others, and featured in Time magazine, the Wall Street Journal and USA Today.

Along with her appearance on The O’Reilly Factor, this has resulted in a series of abusive emails. She has published some of the less offensive threats on Aberdeen Voice, and lodged a complaint with Police Scotland.

One emailer, Chris Bridges, warned her not to offend Trump supporters. “Suzanne Kelly would be well-advised to never set foot outside the UK again, at least not where we can get our hands on her,” he wrote.

“Americans have had just about enough guff from leftist Marxist morons in the UK and we may get it into our heads to rescue the Mother Country from the lunatics currently running it. We have vast cotton fields where the likes of Ms Kelly can turn their hands to profitable labour.”

Another email, which has not been published, suggested she would be “laughing the other side of her face [sic]” when she was being “had by a towelhead”. Another, Sid Williamson, called Kelly “an insignificant little bum wipe”.

The threats were “creepy” but they wouldn’t prevent her from campaigning, Kelly said. “The intent is clearly to worry and intimidate, which is something that not easily done to me at this stage in my life.

“They don’t disturb me or keep me awake at night, but I think it’s disturbing that peoples’ minds work like this.”

Kelly is not optimistic that MPs will agree to ban Trump on Monday. “I don’t believe the debate will go my way, though it probably should,” she said. “I feel like the mouse that roared.”

She plans to respond with a statement on Aberdeen Voice this week, and then says she will “put the bar down” on further interviews. In the autumn she is planning to move to Hastings on the south coast of England.

She agreed that there were ironies in the fact that she was from New York, the city on which Trump has centred his property business. “It takes a New Yorker to break a New Yorker”, she said.

A spokeswoman for Police Scotland said: “Police Scotland received a complaint on 15 January and enquiries are ongoing.” The Trump Organisation in New York did not respond to a request to comment.