There are no available PCR test slots at walk-in or drive-through sites in some parts of England for people with coronavirus symptoms, as issues surrounding the delivery of rapid tests run into a second day.

Briefly on Tuesday morning, the Government website said there were no slots available for PCR tests at walk-in and drive-in test sites across every region of England.

It was later updated to show that slots were available in every region, although there are “none available” in Hertfordshire, Suffolk, Berkshire, the Isle of Wight, Middlesex, Bristol and Mendip.

There are “very few” slots available in London, Surrey, Stockton-on-Tees, South Gloucestershire and South Glamorgan in Wales.

UK Health Security Agency sources said “very high demand” for PCR test slots at sites across the country had led to temporary reduced availability in some areas.

More slots are expected to be made available in the afternoon, although it is not clear whether these will be for later on in the day or for Wednesday.

PCR test kits which are posted to people’s homes, usually arriving the following day, are available.

The public are being advised to try again later if they cannot get a test, which will not be available through helplines.

On Tuesday new guidance came into force for the testing of coronavirus close contacts.

Double jabbed people are now being asked to take a lateral flow test every day for seven days if they come into contact with someone with Covid-19.

But, for the second day running, lateral flow tests are unavailable to be ordered via the Government website, though it is understood that a number were available in the early hours of the morning.

A message on the site on Tuesday morning said there were no tests available for home delivery, although tests can still be collected from pharmacies.

On Monday, the UK Health Security Agency (UKHSA) said that “due to exceptionally high demand, ordering lateral flow tests on gov.uk has been temporarily suspended to fulfil existing orders”.

Ministers have insisted there is no issue over supply, but rather there are constraints on the delivery system for the tests, as they encouraged people to pick up testing kits from their local pharmacies.

However, many people have reported that their local pharmacy is out of stock.

The new guidance says that fully vaccinated people who are in close contact with a confirmed Covid-19 case should take a rapid lateral flow test every day for a week to help slow the spread of the virus.

People who test positive or develop symptoms are still required to isolate, as are unvaccinated people who are “not eligible for this new daily testing policy”, according to the Government website.

Deputy Prime Minister Dominic Raab insisted the issue with ordering lateral flow tests from the Government website is not due to a lack of the tests.He told BBC Breakfast: “The problem isn’t supply and volume, the problem is the allocation and distribution, or the delivery, of it.

“We know that in relation to the online system there were some challenges yesterday and that’s partly because of the proportion they’ve got each day.

“We’re making sure that however people may wish to order them and procure them, we’re ramping up not just the capacity … but the ability to distribute and to deliver.”

On Monday, Health Secretary Sajid Javid said limits on ordering tests are linked to delivery capacity, and said new arrangements have been reached with Amazon and others.

Mr Javid said: “There is no shortage of actual tests that are held by UKHSA. There are tens of millions of tests… the issue, the limiting factor because of the hugely increased demand… is the ability to deliver the tests and having enough capability to deliver the tests because the current arrangements with Royal Mail alone are not enough.

“There are new arrangements that I’ve reached with Amazon and other delivery methods.”

But Labour’s shadow health minister Wes Streeting described Covid testing as a “shambles”.

Mr Streeting said an increase in demand should have been foreseen, and added: “This is a serious problem. Those coming into contact with positive Omicron cases will not be able to follow the rules and get themselves tested on a daily basis.”

There has also been an increased demand for booster vaccines, with many people spending hours in queues at walk-in clinics to get their jabs.

The national booking system was overwhelmed on Monday as over-30s became eligible to book their booster vaccine.

Even with the issues on the website, the NHS in England said it booked in 14 vaccine appointments per second, with more than 390,000 boosters booked.

It is urging people to book their appointments online or by calling 119 to guarantee their vaccine.

Over-18s will be able to book their booster from Wednesday, though some will have already been able to access boosters through walk-in clinics.