For July 2022, the data showed workers aged 50-64, who were reporting long Covid symptoms 30-39 weeks after their initial infection, were 71.2% more likely to be economically inactive than they were during the same period last year.
Long Covid is defined as a person still experiencing symptoms, which can not be attributed to anything else, more than four weeks after first contracting Covid.
Long Covid impacting UK businesses:
Danny Stacy, head of employee intelligence at Indeed, said long Covid is having a major impact on people's ability to work.
Speaking to HR magazine, he said: "Long Covid is a significant issue affecting the already tight UK labour market. Indeed research found that three in four (78%) sufferers have had to stop, reduce or change their work since experiencing symptoms. For those working through symptoms, 98% say their ability to work has been negatively impacted by the disease.
"Many sufferers feel they have no choice but to drag themselves to work, with some citing increased tiredness, reduced physical strength and diminished concentration at work.
"This healthcare emergency is now an employment crisis."
Rates of economic activity were higher among those with long Covid than those without. The data showed 23.3% of people with self-reported long Covid were economically inactive in July 2022, compared with 21.4% for people without long Covid symptoms.
Employers have a duty to support staff suffering with the illness, Stacy added.
He said: "It can be difficult for employers to understand the reality of long Covid sufferers. And with many workforces already stretched, patience for the recovery time could potentially wear thin. But long Covid is not a choice; workers are desperate to get better. When an employer questions the suffering of an employee living with long Covid, the cloud hanging over their head only darkens.
"Employers cannot magically cure staff but their support is key to solving the long Covid crisis. Business leaders must stand by the side of suffering employees, starting by showing compassion, empathy and understanding."
In June 2021 the number of people suffering from long Covid in the UK topped 2 million and in February this year, research from the CIPD found that the illness could be affecting almost half of all organisations.
Long Covid was recognised as a disability in a June 2022 tribunal in a Scottish worker's successful unfair dismissal case.
Daniel Ayoubkhani, data and analysis for social care and health at the ONS, added: "The analysis shows that working-age people are less likely to participate in the labour market after developing long Covid symptoms than they were before being infected with coronavirus. Furthermore, this relationship between self-reported long Covid and inactivity for reasons other than education or retirement is strongest among people aged 50 years or above.
"Long Covid may therefore have contributed to the decreasing levels of participation seen in the UK labour market during the coronavirus pandemic. However, it is unlikely to be the only reason, and further research is needed into other possible factors such as indirect health effects of the pandemic."