More than a third of close contacts of people with coronavirus are still not being reached by the test and trace regime in Buckinghamshire, figures suggest.

It comes as NHS Test and Trace recorded its worst performance on record for the proportion of contacts traced, with health chiefs warning "prompt action" is needed to prevent a tide of hospitalisations as cases increase nationally.

Data from the Department for Health and Social care shows 881 people who tested positive for Covid-19 in Buckinghamshire were transferred to the Test and Trace service between May 28 and September 30.

Test and Trace asks these patients to give details for anyone they were in close contact with in the 48 hours before their symptoms started.

In Buckinghamshire, 2,320 close contacts were identified – also referred to as "non-complex" cases, meaning they could be dealt with through a call centre or online.

But just 65 per cent of those were reached by contact tracers in the four month period, meaning 806 people were not contacted or did not respond.

That was slightly down from the 65.4 per cent reached in the period to September 23.

Across England 62.4 per cent of non-complex close contacts were reached and told to self-isolate by NHS Test and Trace in the latest week to September 30.

Including complex cases – those linked to settings such as hospitals, schools or prisons – the contact tracing rate was 68.6 per cent, the lowest percentage since test and trace began.

Around 34,500 positive cases were transferred to the system over the period – the highest number since the regime launched in May.

Chris Hopson, chief executive of NHS Providers, said the large increase in positive tests, alongside worsening test and trace performance nationally, is "worrying."

“Trust chief executives across the North West, North East and Yorkshire are telling us that Covid-related hospital admissions are rapidly rising," he added.

“We need prompt action to prevent a full-blown second Covid surge.

"We need every member of the public to play their part – hands, face and space – as they did in the first phase of Covid, however frustrating and burdensome they find any restrictions or public health advice."

There are now 87 local authority contact tracing teams live across the country, with more due in the coming weeks, according to the DHSC.

Baroness Dido Harding, who is interim executive chairwoman of the National Institute for Health Protection, said demand for tests is rising with the growing number of cases.

She said: “We are working hard to increase testing capacity to meet that demand and improve turnaround times for tests.

“We have now opened 500 test sites across the UK, an extraordinary achievement.”