Tributes have been paid to Jim Donaldson, the father of DUP MP Sir Jeffrey, following his death.
DUP leader Arlene Foster described him as a "big character" in the Kingdom of Mourne.
The DUP Dromore District branch made the announcement in a Facebook post on Wednesday morning.
"On behalf of the branch we pass on our condolences to the Donaldson family at this sad and difficult time. May they all know God’s strength and comfort in the days and weeks ahead," a statement from the branch chairman and members said.
At the age of 60 Mr Donaldson entered the political fray, following in his son's footsteps. He stood for election for the UUP in 2003 for the Assembly elections. Sir Jeffrey severed his ties with the party to join the DUP later that year in dispute over support of the Good Friday Agreement. His father also quit the party after four decades of membership.
Jim Donaldson, a father-of- eight, had served in the UDR for 26 years and was a member of the Royal Irish Regiment. He would have been aged in his late 70s.
DUP leader Arlene Foster offered her sympathies to the Donaldson family.
"He was a big character in the kingdom of Mourne and someone who served his country with distinction," she said.
"I know he was incredibly proud of his family and they were so important to him.
"Ordinarily we would all want to pay our respects to Jim’s family, especially his wife Annie and his children, but because of the COVID-19 outbreak we are unable to come together to offer our support and sympathy.
"I send my heartfelt sympathy and love to the whole family at this saddest of times. They will know that they are in the prayers of many across Jim’s beloved Northern Ireland and much further afield at this time.”
DUP Newry and Mourne councillor Glyn Hanna and South Down DUP chairman described him as an inspiration saying he would be missed.
"Jim inspired many with his words of encouragement and positivity. He is now safe in the arms of Jesus. The Donaldson family are in our thoughts and prayers," he added.
The Ulster Unionist Party also expressed its sincere condolences to Sir Jeffrey Donaldson MP and his family.
Party chairman Danny Kennedy said: “On behalf of the Ulster Unionist Party I would like to extend sincere sympathies to Sir Jeffrey and the entire Donaldson family circle on the death of a much loved husband, father and grandfather. Our thoughts and prayers are with them all at this sad and difficult time.”
Lagan Valley MLA and UUP Assembly chief whip Robbie Butler added: “I would like to send my condolences to Sir Jeffrey and his family. I know that the whole of Lagan Valley is thinking of them and hope that this will be of some comfort and strength both now and in the days ahead.”
On Tuesday Lagan Valley MP Sir Jeffrey spoke of his heartache of being unable to visit his elderly father Jim as he "fights his final battle". He said the family had only been able to communicate with him through a window.
"It's not an easy time," he told the BBC Stephen Nolan Show on Radio Ulster.
"We're a big family, we're a close family and it's tough at the moment. There are many families in Northern Ireland going through this.
"There isn't going to be a church service so it's a very different scenario.
"It's not just our family, it's the wider local community that are impacted. I just ask that people think about the families that have lost loved ones in recent weeks... who probably feel isolated right now."