The leader of the DUP has repeated a claim the protocol delayed some heart surgeries from going ahead in Northern Ireland.

In response, the Southern Health and Social Care Trust said 20 patients were transferred to the care of the Belfast Trust in August after it could not secure needed replacement kit in the UK or Ireland due to its size.

Sir Jeffrey Donaldson was speaking after meeting with Northern Ireland Secretary Chris Heaton-Harris about the looming threat of a December election after a six-month stalemate at Stormont since May’s election.

The DUP has prevented an assembly and executive from being formed in protest over the protocol, which places additional post-Brexit checks on some goods going from Great Britain to Northern Ireland.

When asked about people on long waiting lists, Sir Jeffrey said work is done every day to help those who require medical care, but the matter “isn’t helped when access to medicines is impaired and inhibited” by the protocol.

“It is not acceptable when people who are waiting on vital cardiac surgery in the Southern Trust are told they can’t have their treatment because parts for an angiogram machine are not available in Great Britain and have to be ordered from Germany.

“And three weeks later, those people are waiting on their surgery and then have to be referred to the Belfast Trust for their treatment. How does that help people on waiting lists?

“How does that help people waiting on surgery, on life-saving treatment, that the protocol is preventing the health service from getting what it needs to provide that treatment? That’s why we need a solution on this.”

Sir Jeffrey recently made similar remarks about delays to heart surgeries in Belfast due to the protocol; the Belfast health trust responded to say there was no substance to his claims.

When asked on Tuesday to clarify if the issue had been with the Southern Health Trust, Sir Jeffrey said: “The problem arose in the Southern Trust and I have had that verified by senior sources from within the medical profession.

“There was a delay and, as a result, the Southern Trust had to make alternative arrangements, which meant patients awaiting cardiac surgery were added to the list of patients in the Belfast Trust, which meant further delay for those patients waiting on that vital treatment.

“So I stand by what I said and I’ve never resiled from it. Unfortunately, some people are not prepared to look beyond the headline, are not prepared to ask the questions.”

In a statement to the PA news agency, the Southern Health and Social Care Trust said replacement parts were sought for some of its cardiac equipment in August from both the UK and Ireland.

It said equipment had to be sourced from Germany due to its size.

“In early August, we experienced some difficulties with our Cardiac Catheterisation Service related to significant faults with the transfer of images and cabling fractures in our Cath Lab,” it said.

“Extensive efforts were made to source replacement parts in both the Republic of Ireland and the UK but unfortunately, given the size of the equipment required, it had to be sourced from the manufacturing site in Germany.

“The replacement cabling was shipped from Germany and the work was able to be completed on Friday August 18. Following checks we were able to recommence the Cath Lab lists.

“Given that the service would be suspended for a period of time, we liaised with colleagues in the Belfast Trust to facilitate the transfer of 20 patients to have their procedures completed.

“There have been no further issues with the equipment since the cabling was replaced.”