UKIP leader Nigel Farage is to visit Scotland 24 hours before a massive Orange Order march "to save the Union", sparking fears of further public disorder.

The right-wing figurehead will address party supporters on the same weekend that 10,000 Orange marchers are expected to take to the streets. The Grand Orange Lodge of Scotland is not part of Better Together but is an officially registered No campaigner. The controversial body is to stage a "British Together" march in Edinburgh on September 13 - just five days before the vote.

The Sunday Herald can reveal that Farage is planning to come to Glasgow on the day before the Orange march. The politician's visit to Edinburgh last year ended in humiliation after left-wing protesters disrupted his press conference and forced him to hide in a pub. A police escort had to bundle him away, amid chants of "racist Nazi scum".

A second trip to Edinburgh, in May this year, was marked by a huge demonstration outside the Corn Exchange venue.

According to a circular by Ukip Scotland chairman Misty Thackeray, Farage's trip is explicitly linked to the referendum.

It said: "Nigel will be joined by a number of leading Ukip figures from all four nations of the UK speaking in resolute defence of our Union.

"Whatever you do, don't miss Nigel's historic intervention in the Battle for Britain's soul!"

Two days later, Ukip will stage a "Battle of Britain Day" at Grangemouth. On September 17 - the day before the referendum - a "special impact mass media event" is also planned.

The internal party communiqué also states there is a "victory roll" scheduled six days after the referendum, which will mark David Coburn getting elected as an MEP in Scotland earlier this year and a vote the party believes will be an "inevitable" No.

John Wilson, an SNP MSP for Central Scotland, said: "The Nigel Farage and Orange Order events clearly raise public order concerns. They also show how the No side relies on these types of right-wing fringe groups."

A spokesman for Better Together said: "As we have stated on a number of occasions, Ukip are not part of our campaign."

A spokesman for Police Scotland said: "Any event will be policed appropriately."

Tensions have grown in the referendum campaign in recent days.

First Minister Alex Salmond called in the police after he was reportedly chased in his official car by a No campaigner.

And Labour MP Jim Murphy, a prominent No campaigner, suspended his 100-day tour of Scotland after being verbally abused and hit with an egg.

Meanwhile, an SNP councillor in South Lanarkshire was revealed to have made an offensive comment about Better Together chief Alistair Darling on Twitter.

Graeme Horne, who represents Hamilton West and Earnock on the council, wrote after last week's debate between Darling and Salmond: "If Darling had pointed his finger at me like that I've [sic] have snapped it off and shoved it up his a***."

Horne was an unsuccessful SNP candidate for Rutherglen and Hamilton West in the 2010 General Election, losing by more than 21,000 votes. He was also election agent to SNP MSP Christina McKelvie.

An SNP spokesperson said of Horne's comments: "We've always said that people must be respectful in the language they use regarding the debate on Scotland's future. Alistair Darling's finger pointing may have been unattractive, but that is no excuse for abusive language."

Horne did not respond to a request for comment.