Almost 20,000 patients have waited longer than the target-time for treatment since Scotland's newest hospital opened its doors, according to the Liberal Democrats.

A total of 19,577 out of the 159,123 people who have attended accident and emergency (A&E) at the £842 million Queen Elizabeth University Hospital (QEUH) in Glasgow waited for longer than four hours to be seen and either admitted, transferred or discharged.

Since the hospital opened in May 2015, it has recorded an average performance rate of 87.7% against the Scottish Government's 95% target, with the benchmark hit during two weeks out of 92.

The worst performance since weekly reporting began was in the week ending January 8, when 74.8% were seen within four hours and 465 patients waited longer.

Lib Dem health spokesman Alex Cole-Hamilton: "If you're a potential patient in Glasgow, this new analysis reveals a real horror story.

"It confirms that, for almost two years, SNP ministers and health bosses have been utterly unable to get a grip of the situation there.

"We were told they would be 'consistently delivering' against the A&E target by last spring.

"In fact, they are consistently under-performing. Their interventions to date evidently haven't worked and the situation is getting worse.

"A&E staff are working incredibly hard in an often stressful environment.

"Health bosses and SNP ministers need to perform an urgent operation on the QEUH and ensure they have the support and resources they need to do their jobs."

A statement from NHS Greater Glasgow and Clyde said: "We are fully committed to ensuring that patients are seen, treated and either admitted or discharged as quickly as possible.

"Performance figures for emergency departments, by their nature, will always fluctuate on a day to day, and even week to week, basis.

"However, the majority of patients were seen, assessed, treated and either admitted or discharge within the four-hour target.

"Most of those patients who did not meet the four-hour target were either admitted or discharged shortly thereafter.

"We apologise to those patients who waited longer than this. However, medical attention will always be clinically prioritised for those who most urgently require it.

"We still have work to do, however our staff have been working incredibly hard putting in new measures to ensure we continue to head in the right direction."

A Scottish Government spokeswoman said: "A&E in Scotland is the best performing in the UK by a considerable margin.

"It is testament to the work of NHS staff across the country that more than nine out of 10 patients were seen within four hours in Scotland's core emergency departments.

"As we have seen throughout the year, A&E figures will fluctuate week-to-week and we are monitoring this closely to ensure no-one is waiting longer than absolutely necessary.

"We are committed to putting in place long-term, sustainable change so that our hospitals can maintain high levels of performance during peaks and troughs of activity.

"We know that a small number of sites are still facing particular challenges with demand and performance, we have delivered record investment and increased levels of staffing in our hospitals to make sure that those health boards facing challenges receive the support they require."