As first reported by Sky News, Simon Thompson had been in talks to leave the company after his credibility was challenged by MPs who recalled him for questioning at the Business, Energy and Industrial Strategy (BEIS) committee.

He was accused of giving "inconsistencies" in evidence before the committee.

The company said it was in "advanced stages" of appointing a new chief executive and Mr Thompson will remain with the business until 31 October as part of the transition.

The former state-owned company was locked into a bitter dispute with employee members of the Communication Workers Union (CWU) which ended last month when an agreement on pay and employment terms was settled.

The settlement of that dispute has been listed as a reason for Mr Thompson to leave now.

"The changes we have made, the infrastructure we have put in place, and the agreements negotiated with our trade unions mean that Royal Mail now has a chance to compete and grow," he said.

"That is what I have always wanted, and it is now the right time to hand over to a new CEO to deliver the next stage of the company's reinvention."

Mr Thompson took on the chief executive role just over two years ago in January 2021. Prior to his appointment he served as a non-executive director of the board since 2017.

He thanked his team for their support in what he acknowledged was a "difficult and important time of change".

The postal delivery company had been under pressure to implement modernising reforms after reporting millions of pounds of losses.

In October it announced a process to make 5,000 to 6,000 roles redundant by August.

The financial hit of industrial action was estimated to have cost £200m in the first nine months of IDS's financial year to the end of December.

But the CWU general secretary laid the blame on Mr Thompson.

"Simon Thompson is one of the key individuals responsible for the financial crisis that Royal Mail Group has created over the course of the last year," Dave Ward said.

"The chief executive was also one of the key people responsible for the appalling mantra of 'it's our business to run' - which saw the employer openly attack its own workforce on a relentless basis, including developing a culture of imposition and creating service quality and USO [universal service obligation] failures on a scale which threatens the future of the company.

"However, we recognise that the chief executive was only one of the senior leadership team responsible for the unacceptable actions and behaviours of managers across the UK throughout this dispute. Further change in Royal Mail Group's leadership team is vital."

Royal Mail was also subject to a disruptive cyber attack and reported a breach of customer data in the past year.