US presidential elections: Case against Ted Cruz over eligibility

As per the constitution only US-born citizens are eligible to run for presidency. Cruz was born in Canada

Top Republican candidate Ted Cruz has been slapped with a lawsuit challenging his eligibility to serve as US president over citizenship issues, raising doubts about his status ahead of the crucial South Carolina primary.

In his lawsuit, Lawrence Joyce from Illinois has objected to Cruz's placement on the Illinois primary ballot next month.

As per the American constitution, only US-born citizens are eligible to run for presidency. Cruz, who was born in Canada, argues he is a natural US citizen as his parents were US citizen.

At a CNN-townhall, the 45-year-old Texas senator said the issue has been clear from the very first day of the republic.

"I was a citizen by birth, by virtue of my mother's citizenship, so I've never been naturalised. I've never breathed air on this planet when I was not a US citizen," he said.

"It was the act of being born that made me a US citizen. So under the law, the question is clear. There will still be some that high to work political mischief on it, but as a legal matter, this is clear and straightforward," Cruz said.

Republican presidential frontrunner Donald Trump described this as a big problem. He has threatened to sue Cruz on this.

"I don't think he's got a very good chance of getting it. But he was sued today on the fact that he was born in Canada. It's a big problem," Trump said last night.