THE family of a Renfrew man hailed as a “stalwart of the SNP” by the First Minster have said they are “numb” following his sudden death at the age of 34.

John Clark, who was head of office for Renfrewshire North and West MSP Derek Mackay, died on Sunday while on holiday in the USA.

Heartfelt tributes have since poured in for the SNP activist, who was known for his “jovial character”.

John’s sister, Michelle Clark, said: “The unexpectedness of this has left us all numb.

“John touched the lives of so many and was a loving brother. Our family are understandably devastated.”

First Minister Nicola Sturgeon said she was “devastated” by the news and described John as a “true giant of a man, in every sense” on social media.

She tweeted: “John was a stalwart of the SNP.

"As well as Derek’s office manager, he was a committed activist and valued member of our National Executive Committee. A true giant of a man, in every sense.

“My love and thoughts are with his family, friends and colleagues.”

Mr Mackay said John, who grew up in the Kirklandneuk area of Renfrew, had been a “rock” to him.

He added: “John, a gentle giant of a man, is irreplaceable as he was the most trustworthy, loyal and hard-working person I have ever had the privilege to call my friend.

“John was a rock to many, not least myself. He was one of life’s good guys.”

Renfrewshire Council’s SNP group said John was tipped for a “bright future” in politics and was highly regarded within the party.

John, who more recently lived in Paisley, narrowly lost out on becoming a councillor in Renfrewshire two years ago, having stood as a candidate for the Paisley Northeast and Ralston ward.

He was also known as a committed fundraiser, having coined in nearly £2,000 for the British Heart Foundation by walking 42 miles of a 62-mile trek from Glasgow to Edinburgh in July.

John was in Denver, Colorado, as part of a dream holiday to the States when tragedy struck.

A cause of death has not been disclosed.