Staff at Angus MacDonald’s constituency office in York Arcade, Grangemouth were the victims of an attack aimed at the SNP elected member when they opened a posted piece of mail on Wednesday, August 1 which contained posters showing Mr MacDonald in a negative light – and one of the posters, to their horror, was smeared in faeces.

Mr MacDonald, who is furious his hardworking staff were subjected to such a disgusting attack, said: “I was deliberately targeted with a rather unpleasant, apparently anonymous, letter last week in the form of two posters which, at first, seemed like harmless name calling.

“However, it wasn’t until unfurling the second of the two posters my staff encountered a brown substance smeared on the letter in a way that was set out to cause the most disturbance.

“I have a dedicated team of hardworking staff who operate my constituency office in Grangemouth tirelessly. Their sole purpose is to support me in my work for my constituents in the way they rightfully deserve to be represented.

“They open mail and answer calls from any constituent – therefore the aim of the disgruntled poster was off and the intended target missed entirely.”

Mr MacDonald had his own message to deliver to the person or persons who sent the package.

He said: “To those who seek to abuse and cause damage to people for the sake of making a point – the net is closing in and your time in the shadows is nearly up. By all means disagree and put your point across – but be careful of taking that step too far as, before long, the spotlight will find you and the consequences of your actions will only be yours to bear.

“The police have been informed and are working hard to ensure the scourge of this type of abuse is stamped out. This type of targeted abuse is not welcome in our society and we should not tolerate such behaviour.”

Mr MacDonald’s staff stated police officers had attended their office this week and removed the offending items as evidence in their ongoing investigation of the incident.

Chief Inspector Damian Armstrong said: “We were called to the constituency offices of Angus MacDonald MSP in response to a complaint from staff about a letter which contained offensive material.

“Officers seized this letter and its contents and enquiries are ongoing to identify the sender.”

Mr MacDonald noted the worrying trend of targeting elected officials and mentioned an incident earlier this year which saw the Scottish Parliament sealed off after an office received white powder in an envelope.

He also referred to “recent tragedies” like Labour MP Jo Cox who died in June 2016 after she was shot and stabbed multiple times by far right extremist Thomas Mair who is now serving a life sentence in prison.

Mr MacDonald said: “In the current political climate, politicians could be forgiven for being anxious when experiencing various levels of abuse – abuse in the public spotlight is not uncommon, and it certainly is not a new phenomenon.

“It can come in all forms and, with the rise in social media use, it’s only a click of a button away. The majority of abuse is words – they can be taken or left – however, when it comes in the form of something physical or tangible, this leaves more than just a ringing in your ear.