Royal Mail delivered less than 80% of first class post on time in the first quarter, it said on Friday, missing its delivery targets set by the communications watchdog.

The company said 79.1% of first class mail arrived within one working day in the three months to June 30.

It represents another quarter in which Royal Mail has missed its delivery targets set by Ofcom.

Under the communications watchdog’s rules, 93% of first class mail must be delivered within the timeframe, excluding Christmas.

Royal Mail said 93.5% of first class letters arrived within two days, a small improvement on the same period last year, when 91.6% of first class post was delivered in the timeframe.

Royal Mail also missed its 98.5% target of second class post being delivered in three days, delivering only 94.1% on time.

In May, Ofcom said it was investigating the postal service for missing its delivery time targets for the year to March 2024.

The watchdog fined the company £5.6 million for failing to meet its first and second class delivery targets in the financial year ending March 2023.

The postal service is in the process of being bought out by Czech billionaire Daniel Kretinsky in a £3.57 billion deal.

International Distribution Services, the parent company of Royal Mail, agreed a takeover deal by Mr Kretinsky’s EP Group in May.

But the deal is not yet completed, after the Cabinet Office launched a review process into the bid under the National Security and Investment (NSI) act.

Royal Mail said it has taken steps to improve its delivery time, including employing more permanent staff, bringing in new rules to cut down on sick days and improving retention.

It has also established a so-called quality control centre to manage disruptions.

The company is in the process of adapting to the declining volumes of letters and growing demands for larger parcels and next day deliveries.

This has included removing half of domestic flights this year. More mail is now being transported by road which is more reliable, has greater capacity for growing numbers of parcels, and is better for the environment, it said.

Royal Mail chief operating officer, Alistair Cochrane, said: “Delivering a high quality of service continues to be our top priority and I am pleased this ongoing focus has ensured improvements across the quarter.

“We know there is more to do and will continue on this path, enacting steady changes to our operational model to bring long-term improvements to our quality of service.”

An Ofcom spokesperson said: “Royal Mail’s performance hasn’t been good enough.

“Last year, we fined the company and we’re currently investigating its latest failure to hit its annual delivery targets.

“We’ve been pressing the company on what it’s doing to turn things around. Royal Mail recently published an update on its improvement plans.

“It’s made some progress recently, but there’s still more to do. We’ll continue to hold Royal Mail to account, and take action on behalf of its customers.”