The Government has been urged to launch an investigation after the email addresses of almost 300 new recruits to its coronavirus contact-tracing programme were shared by mistake.

The error prompted an apology from outsourcing firm Serco which said it would “review its processes” following the incident in which it had emailed new trainees to tell them about training.

A total of 296 addresses were included in a CC (carbon copy) section of an email rather than BCC (blind carbon copy), meaning they were visible to recipients.

The company are helping to sign people up to support efforts to track and trace cases of Covid-19 to help reduce the spread of the disease in the UK.

In a letter to Cabinet Office minister Michael Gove, Labour shadow cabinet office minister Rachel Reeves called for urgent action from the Government to restore public confidence following the error.

She said: “To ease the lockdown restrictions, a proper system of test, trace and isolate needs to be in place.

“The Government needs to make sure it is and that the public have faith in it.

“It has never been clear what expertise or specialist knowledge Serco can bring to contact tracing.

“It now appears that they are struggling to implement even basic aspects of data privacy.

“We need some clarity from the Government about why and how Serco came to be awarded this contract and we need reassurances that the contract tracing programme is in safe hands.

“The Prime Minister has promised it will be up and running by June 1, if we are to ease lockdown safely then it is essential that the Government gets this right.”