ROYAL MAIL’S bosses should be investigated for corporate corruption over “secret talks” to break up and sell the 500-year-old public service, the Communication Workers Union (CWU) said today.

General secretary Dave Ward said he is extremely concerned about a potential sale to Luxembourg-based private equity firm Vesa Equity Investment, warning that the move could threaten thousands of jobs at the privatised company and worsen services.

In a letter to Business Secretary Kwasi Kwarteng, Mr Ward welcomed the minister’s decision to investigate the reports “with urgency.”

Last month, Mr Kwarteng, who could be appointed Chancellor of the Exchequer by incoming Tory Prime Minister Liz Truss today, warned Daniel Kretinsky, Vesa’s Czech billionaire owner, that he risks facing a national security probe if he increases his stake in Royal Mail to more than 25 per cent.

The company’s bosses pledged to fully co-operate with the review into the businessman, who also has stakes in Sainsbury’s, Macy’s and West Ham United Football Club.

But in his letter, Mr Ward said that the announcement was made less than 48 hours after the CWU, which has already launched strike action against below-inflation pay awards at Royal Mail, wrote to bosses expressing its concerns.

The union’s members have also overwhelmingly backed walkouts over the abandonment of union-agreed changes to working conditions.

He wrote: “We believe that secret talks have been going on behind the backs of the workforce and the public for some time and that this explains the reason why Royal Mail walked away from all our agreements on change and have deliberately manufactured the disputes that are currently taking place.”

This was done to “facilitate a predetermined outcome, that being the takeover of the Royal Mail Group by Vesa,” Mr Ward added.

“It is the view of the CWU that what has taken place has a strong possibility of involving corporate corruption.”

Mr Ward urged the Business Secretary to “investigate whether these talks amount to insider trading and whether board members have received or are due to receive additional benefits if the takeover goes ahead.

“The CWU is unequivocal in [opposing] this potential takeover – it is against the interests of workers and the public.”

Royal Mail was contacted for comment.