The NHS coronavirus test-and-trace system designed to prevent a second deadly wave is not expected to work at full speed until September or October, the Guardian has learned. Tony Prestedge, the chief operating officer of the NHS scheme, admitted in a webinar to staff that the programme would be “imperfect” at launch, adding that he hoped it would be operational at a world-class level within three to four months. It comes as a leaked email from the chief executive of Serco – one of the main companies contracted to deliver the service – revealed how he doubted the scheme would evolve smoothly but said he wanted it to “cement the position of the private sector” in the NHS supply chain. The disclosures come as scientists said lockdown measures should not be eased until the test-and-trace service is well established. The system, which tracks those who have contracted coronavirus and anyone they have been in contact with, before asking them to self-isolate, was rolled out across England last week with the help of 25,000 contact tracers. Justin Madders, a shadow health ministers, said the idea that the system may be months away from being fully operational was “deeply concerning”. In a webinar for staff, Prestedge, a senior banker drafted in to help run the programme to trace infected people, said: “I am sure when Dido [Harding, chief executive of scheme] announces this service later she will make clear that it is an imperfect service at launch that we will improve over time and make it world-class by the time that we are moving towards the September or October time.” Prestedge, who is due to take up the post of deputy chief executive of the bank Santander UK, said: “We know it will be imperfect, we know it will be clunky but we ask you to help us improve the service.” The video was recorded on 27 May, just before the government announced the scheme would launch. In following days, the health secretary, Matt Hancock, laughed off claims in an interview with Sky News that he had rushed to introduce the system amid the political row over the alleged breach of lockdown rules by Boris Johnson’s chief adviser, Dominic Cummings. Initially an app was supposed to be part of a national rollout of the test-and-trace programme, but this element has been beset by problems and instead the tracing system started without it. Prestedge said he expected test and trace to be running for 24 months and that initially test results would take two to three days to arrive, with the hope this would improve over time. A leaked message from Rupert Soames, Serco’s chief executive, also revealed his own concerns about the initial months of the programme. Serco is among a number of companies that are recruiting, coaching and managing contact tracers who do not have clinical training. They have taken the bulk of the work, recruiting 10,000 of the new 25,000 contact tracers after being awarded an initial fee of £45.8m, which could rise to £90m. In an email forwarded to staff, which was then immediately recalled, a message from Soames said: “There are a few, a noisy few, who would like to see us fail because we are private companies delivering a public service. I very much doubt that this is going to evolve smoothly, so they will have plenty of opportunity to say I told you so.” It continued: “If it succeeds … it will go a long way in cementing the position of the private sector companies in the public sector supply chain. Some of the naysayers recognise this, which is why they will take every opportunity to undermine us.” Soames also asked managers to make sure employees behave in a way to survive the “Daily Mail test”, explaining that this meant “that you would not mind their behaviour being described on the front of a national newspaper”. “It is inevitable that someone somewhere is going to behave badly,” he said, adding that he wanted to know immediately to resolve the issue. He continued: “At Serco we have a fair amount of experience managing difficult issues and one of the hard lessons we have learned is that the truth we can manage, it’s the evasion or cover up that destroys you.” Serco said the message from Soames was not recalled but may have been forwarded to a wider group of employees in an email that was recalled. Madders said: “The government’s own scientific advisers have said that an effective track, trace and isolate system must be fully operational before the lockdown is relaxed further so any suggestion that we may be months away from that is deeply concerning. “We need assurances from ministers that they urgently ensure an effective system is in place and working effectively. To move ahead with further easing of the lockdown without this vital system working fully would be a huge gamble that no responsible government should take.” Those working for test and trace have raised concerns about a slow start. The Guardian was shown an email dated 2 June from one provider to their team that said: “We did experience some teething issues yesterday particularly with CTAS [the contact tracing and advice service software] and this feedback has been shared with the clients.” It told those working for the service that the data volumes were still very low and there would be times when no records were available. Staff were told to do e-learning at this time. On 1 June, an email told staff ttheir hours would be reduced owing to a lack of cases coming through. Another email said: “With the operations in its early stages, the data volume at the moment is not at full capacity, and as such you may experience prolonged periods of waiting for a case.” One anonymous worker said: “The communication and training have been terrible from the start and I’m yet to know anybody who has made a call to a member of the public. “We have been paid to do nought and been dossing all day every day on government money. I have personally been sat in my garden sunbathing, drinking and chilling with my pals for two and a half weeks now, occasionally coming inside to stop my computer going to sleep and check my emails. Normally I would be happy about this but when the countries public health is at risk. It is a tragedy.” A Department of Health and Social Care spokesperson said: “The new NHS test and trace service is up and running and is helping save lives. Anyone in this country can now book a test and the majority who book a test get the results back within a day. We have over 25,000 contact tracers in place, who have all been trained and are fully supported in their work by public health experts.”