A man was detained by police after an incident involving Ukip leader Nigel Farage as he campaigned ahead of tomorrow's crucial Aberdeen Donside by-election.

Mr Farage scrapped plans to meet council officials for high tea in Aberdeen before he was faced with eight protesters outside a bar in the city where he planned to finish his whistlestop tour with a pint.

One of the protesters quizzed Mr Farage on his controversial immigration policies and accused him of being a racist.

When the party turned to head into the bar, Ukip's London chairman was sprayed on the back with a bottle of coke. Police officers placed the protester into the back of a police van.

Protester Sean McVeigh, 34, of Aberdeen, said: "We just wanted to question him about his policies. We believe that he is a racist.

"He's not a nice person as far as I'm concerned. I don't think he's going to make much progress here, I don't think Scottish people are really interested in his agenda."

A Police Scotland spokesman confirmed a man had been detained.

The latest incident comes after Mr Farage faced protesters during a trip to Edinburgh last month. He was campaigning with the local Ukip candidate, Otto Inglis.

Mr Farage had hoped to visit the city's Town House to meet independent councillor Marie Boulton, who had been baking cakes for the Ukip leader.

She had hoped to prove Scottish people were friendly following his recent visit to the capital.

However, the tea party was cancelled on advice from police after about 30 protesters began to gather outside.

The Ukip leader and Mr Inglis instead knocked on doors and spoke to local residents.

Mr Farage said Ukip would make "significant progress" in the poll.