Patients faced record delays for a range of medical tests at Gloucestershire Hospitals Trust in May, as hospitals across England saw waiting times rocket due to the coronavirus pandemic.

Medical experts warn growing waiting lists could spell trouble in the coming months as lockdown eases and referrals rise, with stark challenges facing health services.

NHS trusts report on wait times for 15 key tests at the end of each month, which are used to diagnose a wide range of diseases and conditions, including cancers, heart failure, and hearing problems.

According to NHS rules, after someone is referred for one of the tests, they should have it completed within six weeks.

But NHS England data shows 1,853 patients at Gloucestershire Hospitals NHS Foundation Trust had been waiting longer than that at the end of May.

At 43.4 percent of those on the waiting list, this was the worst performance for the month since comparable local records began in 2014.

The national standard is that fewer than 1 percent of patients should wait six weeks or more.

The previous May, the figure stood at just 51 patients (0.6 percent).

Of those who were not seen on time, 74 had been on the list at least 13 weeks.

Imelda Redmond, national director of watchdog Healthwatch England, said the figures were not surprising given the need to focus limited resources on tackling Covid-19.

“However, the rise in the figures shows starkly the challenge facing the NHS,” she added.

“It is therefore vital that the NHS prioritises those with the most urgent and serious needs, as well as those who have been waiting a very long time for a diagnosis."

Dr Rebecca Fisher, from charity the Health Foundation, said the hold-ups “could be storing up trouble” for the health service.

She added: “The number of referrals is likely to rise rapidly in the coming months and the NHS faces a difficult trade-off between keeping staff and patients safe from Covid-19, and ensuring that people don’t come to harm as a result of delays.”

The most common type of test to see delays at Gloucestershire Hospitals Trust in May was gastroscopy, which can be used to diagnose various problems with parts of the digestive system – 620 people had been waiting at least six weeks.

​This was followed by 451 patients waiting for colonoscopy, which is useful as a check for certain bowel conditions.

​Another 339 people were held up for echocardiography, which is used to spot heart failure.

An NHS spokesman said: "Despite responding rapidly to the coronavirus pandemic and the need to ensure over 100,000 patients could receive hospital care, NHS staff also provided more than five million urgent tests, checks and treatment in a safe way during the peak of the virus.”