AN SNP stalwart has demanded the First Minister fulfil a manifesto promise to complete a stalled major infrastructure project or resign.

Fergus Ewing, the MSP for Inverness, spoke at a “crisis summit” on the future of the A9 organised by the Inverness Courier this week and told the paper that Humza Yousaf must oversee the completion of a dualling project which has been stalled for years.

The A9 is single carriageway between Inverness and Perth – something thought to contribute to the high number of crashes and deaths on the road, considered one of Scotland’s most dangerous.

Ewing, a former minister who has reinvented himself as an outspoken backbench rebel, said he could no longer support the Government unless it delivered a comprehensive plan to enlarge the road between the two cities.

Since 2011, the Scottish Government has been officially committed to making the A9 into a dual carriageway between Perth and Inverness, though the project has experienced major setbacks.

READ MORE: Civil engineers tell Holyrood they knew target to dual A9 by 2025 would not be met

The SNP’s 2011 manifesto said: “The A9 is a key artery in Scotland’s transport network and we will continue to invest in improvements to the road on a continuing and progressive basis.

“We are fully committed to dualling the A9 from Perth to Inverness and have fast-tracked work to extend the dualled section at Crubenmore.”

Ewing detailed three key points the Government must hit in producing a plan to make progress on the project to ensure his continued support of the administration, of which he has become a fierce critic.

Speaking after the event, which also featured Transport Secretary Màiri McAllan, he said: “Well, I was grateful for the Cabinet Secretary appearing today, but I'm afraid to say that there weren't specific guarantees to the questions that were asked.

“There was no specific assurance that she will, in Parliament, in the statement give a completion date by which the A9 must be dualled.

“Secondly, there was no clear commitment to give in her statement a clear detailed schedule of when each of the remaining nine sections will be completed.

“And thirdly, there was no absolute guarantee that the money will be spent in the Highlands as opposed to in the central belt.

“So what I'm saying today is that, for me, for the Cabinet Secretary, for the First Minister – we must deliver.

“This is a matter of honour. It's a cast iron guarantee and quite frankly, if the First Minister cannot deliver, he must consider his position.”

The SNP MSP added: “For me this is a matter of honour, I will not stand here in a year’s time and continue to support this Government unless they deliver and deliver quickly on all of those three things.

“And if they don’t do that then, frankly, I don’t think we deserve to continue to be in government.”