Footage has emerged of an electronic voting machine somewhere in the US that appears to force the voter to select Mitt Romney as their chosen presidential candidate despite clicking Barack Obama's name.

The clip, posted to YouTube by the user centralpavote - suggesting the voter is in Pennsylvania - shows the voter selecting Obama's name on the machine's touchscreen, only for Romney's name to be highlighted.

The user later described on social media site Reddit that he had tried selecting other candidates' names and had no problem, suggesting that the issue only arose when attempting to vote for Obama.

According to his Reddit post he finally managed to vote for Obama by finding a 'small white sliver' of the screen that would allow his name to be highlighted.