UKIP's Scottish chairman has boasted about going undercover to spy on political opponents in order to protect Nigel Farage on his recent trip to Scotland.

Arthur Misty Thackeray bragged about how he and a colleague "covertly" attended a meeting of groups planning an anti-Ukip protest last week.

In an email to party members, Thackeray said he had taken the security "counter measures" ahead of a visit to Edinburgh by Ukip leader Farage, which attracted a large protest from groups opposed to his anti-immigration message.

Updating Ukip members on the "fantastic" event, Thackeray wrote: "As you will probably have seen there was a counter protest by far-left extremists aimed at intimidating our members.

"The threat posed by these violent groups is such that Nigel now has a personal security detail," he said.

"What you may not be aware of are the counter measures we deployed to address this protest, which included [treasurer] Rob Sale and I covertly attending the Radical Independence Campaign (RIC) planning meeting."

RIC said Thackeray and his friend had been clocked as soon as they walked in.

A spokesman said: "This just goes to highlight the bizarre nature of Ukip politics, which have no place in 2014."