London: British police have arrested a man on suspicion of making racist threats online against Gina Miller, who has challenged the government over how to trigger Brexit in a legal battle that has inflamed passions in Britain.

Miller, 51, an investment manager who says she does not want to block Brexit but rather to ensure parliament is properly involved in the process, has received death threats and abuse since featuring prominently in media coverage of the case.

Britons voted to leave the European Union by 52 to 48 per cent in a June referendum, and the nation remains bitterly divided over the issue.

Miller has been cast by critics as an establishment figure trying to thwart the will of the people, which she denies.

London’s Metropolitan Police said on Wednesday they had arrested a 55-year-old man in Swindon, western England, on suspicion of making “racially aggravated malicious communications” against a 51-year-old woman.

Miller confirmed the arrest was in connection with threats she has received.

“It is one of several ongoing police investigations,” she said in an email to Reuters.

Police said the arrested man was taken to a police station in Wiltshire, western England, and later released on bail. The state prosecution service is considering whether to bring charges.

As part of the same investigation, police also issued a “cease and desist” notice to a 38-year-old man from Fife, Scotland, they said.

The government is appealing to the Supreme Court this week against a November ruling by the High Court that it needs parliament’s assent before it can trigger Article 50 of the European Union’s Lisbon Treaty to formally begin Brexit talks.

On the opening day of the four-day hearing, Supreme Court President David Neuberger alluded to the abuse and threats directed at Miller and others connected with the legal battle.

“Threatening and abusing people because they are exercising their fundamental right to go to court undermines the rule of law,” he said.