Scottish Tory leader Douglas Ross challenged Shona Robison on the "crisis", as he revealed figures uncovered by his party showed long waits for patients and ambulances "backing up" outside hospitals.

The FOI data also showed patients in the most urgent category waiting up to 10 times the six-minute target time for an ambulance to get to them.

Mr Ross said about half of patients in this purple category had suffered a cardiac arrest, as he asked Ms Robison: "Why should anyone whose heart has stopped be waiting so long for an ambulance to arrive?"

Ms Robison, who was standing in at First Minister's Questions at Holyrood as Humza Yousaf was unwell, said the latest figures from the Scottish Ambulance Service (SAS) put the median response time for these calls at seven minutes and 32 seconds.

But she said: "I accept that is too long, and I accept there will be people waiting outside of those times."

She also told MSPs that some ambulances "are taking longer than they should to turn around at the front door of our hospitals".

While Ms Robison said "similar pressures are being felt throughout the UK" as winter challenges impact on the NHS, she added: "Patient safety remains our top priority and I would apologise to anyone who has either experienced any waits for an ambulance to reach them or indeed has had to wait too long at A&E."

Mr Ross told her the latest figures from the SAS show "one in every 10 ambulances in Scotland sat outside hospitals for hours waiting for patients to be admitted".

He added: "That means in just one week, 700 ambulances across the country were stuck outside hospitals for hours."

Mr Ross told Ms Robison, a former health secretary in the Scottish government, that one ambulance was waiting outside a hospital in Ayrshire for 15 hours.

He added that another ambulance "waited over 10 hours" outside a hospital in NHS Grampian, while in the NHS Lothian area an ambulance and its patient had to wait more than 11 hours.

Mr Ross said: "Purple calls involve the most life-threatening, dangerous situations for patients.

"Half of the patients in that category have had a cardiac arrest and these calls have a target response time of six minutes.

"Yet our FOI request revealed that some patients are waiting more than half-an-hour, and others are waiting 10 times longer than the target."

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Ms Robison insisted the ambulance service is "working hard with health boards to minimise delays in hand over times".

She also said the service had received an extra £50m from Holyrood as part of planning to help the NHS prepare for winter.

She said: "Scottish Ambulance Service staffing is up 50% under this government and we have record levels of investment in our health service, including in our Scottish Ambulance Service."

However she said "the investment that has been made in our Scottish Ambulance Service and in our health service is absolutely not down to any of the resources that are being given to us by the UK government".

She told MSPs: "I have it in black and white that next year all the money that is coming from the UK government for health amounts to £10.8m. That is enough for five hours capacity in the NHS."

She claimed that as a result, it is a "bit rich for Douglas Ross to come to this chamber talking about the performance of our Scottish Ambulance Service or indeed our health service more generally" when the Conservative UK government has "singularly failed to provide the funding for our health service".