More than 150,000 cervical screening samples have been piling up in laboratories across England waiting to be tested, according to a new report.

The National Audit Office (NAO) said changes to testing arrangements led to a huge backlog that is still being tackled.

It also found that, at one point last year, only one in three women undergoing a smear test received their result within the recommended 14 days. This suggests hundreds of thousands of women have had to wait longer to find out whether they need further tests or treatment.

Robert Music, chief executive of Jo’s Cervical Cancer Trust, said over the past year many women have contacted the charity with concerns over delays in their results.

“It is simply not fair that women should be put under undue stress as a result of failings in the programme management,” he said.

This follows news that record levels of UK women are overdue a smear test, due to embarrassment or fear around the cervical screening process. Theresa May discussed the issue in the House of Commons last week, while campaigner Chloe Delevingne had a smear test live on morning TV to raise awareness. 

[Read More: Putting Off Your Smear Test? Here’s Why You Should Book Your Next Appointment]

The NAO study found that not one NHS screening programme – including those for breast and bowel cancer – met national targets for how many people should be screened.

A new lower threshold target has been introduced to reflect the lowest level of performance that programmes are expected to reach. Some are now meeting this target, although it’s worth noting this is the minimum number of people the NHS suggests should be seen.

NAO experts blamed problems with dated IT systems, meaning concerns remain that people may miss out on cancer screening invitations. It follows serious incidents reported last year regarding the cervical and breast cancer screening programmes, when thousands of women were not sent invitations.

The roll-out of a cervical screening programme to first test samples for human papillomavirus (HPV) – which is thought to cause most cases of cervical cancer – was announced in 2016 but is not expected to be fully introduced until December 2019.

With the new system, cervical samples collected from women will be tested for HPV first, to identify those which would benefit from further testing.

The number of laboratories needed to analyse results will be cut from 48 to nine, meaning staff have been “leaving in search of greater job security”. This has led to a “decline in performance against turnaround time targets” and a build-up of samples waiting to be tested, the NAO said.

Some 98% of women should receive their results within 14 days of their cervical screening appointment, but this target has not been met since November 2015.

In March 2018, only 33% of women were getting their results on time. By December, this had improved to 55%.

It comes when the number of women attending smear tests has dropped to the lowest it’s been for two decades. Screening is important, around 3,000 cases of cervical cancer are diagnosed each year in the UK.

Music said: “We still have almost a year until HPV primary testing is fully rolled out in England and ongoing mitigation is vital to ensure we do not see further backlogs and the process is as seamless as possible for women.”

Labour MP Meg Hillier, chairwoman of the Commons public accounts committee, said: “It is unacceptable that these important screening programmes are being let down by complex and ageing IT.

“The Department of Health and Social Care, NHS England and Public Health England need to get this fixed.”