Baroness Dido Harding has rejected calls to stop referring to her service as “NHS Test And Trace”, saying “that is its name”.

The Tory peer also suggested that the controversial £12bn system, which is run by the Department of Health and Social Care and uses several private firms, deserved the NHS tag because it was free for the public to use just like the health service.

Harding further pointed out that NHS labs played a key part in its work, but said she was proud of the private sector’s role and declared that “we have built a retail organisation larger than Asda” in just a few months.

The former boss of telecom firm TalkTalk, who was given her current role by health secretary Matt Hancock earlier this year, made her defence of the service as she gave evidence to MPs on the Commons science and technology committee.

NHS Test and Trace has come under repeated criticism not just for its failure to hit tracing and test result turnaround targets but also for its use of big contractors such as Serco and Deloitte.

Several senior NHS insiders have told HuffPost UK they fear the use of the NHS logo is undermining the health service’s brand.

Labour MP Zara Sultana pointed out to Harding that of the 35 organisations listed as data processors for the service, just four were NHS bodies, four were privately-run Lighthouse Labs, four were Public Health England and one was the Ministry of Defence.

As the remaining 22 were all private companies such as Deloitte, Serco, G4S and Amazon, Sultana asked the Tory peer if it was accurate to keep referring to the system as “NHS Test and Trace”.

“Yes I do, that is its name,” Harding replied. “NHS Test and Trace is a free at the point of need service that we’ve built together, as you’ve rightly listed, with a whole group of different parts of society to deliver something at extraordinary scale.

“But it absolutely meets our basic fundamental NHS values as a clinical service available to everyone when they need it…plainly the NHS [lab] tests are an integral part of our overall ‘team of teams’.”

In the same evidence session, former King’s Fund chief Professor Sir Chris Ham said that the decision to hire private firms had shown how ministers were “biased” against localising the service.

“The difficulty we have is the government has built a test, trace and isolate system too much biased towards the national and too late in providing the resources and staff at a local level where most of the effective work on contact tracing has to be done.

“On contact tracing specifically, the government chose to go down the route of bringing in private sector expertise through Serco and Sitel to run the national system and only belatedly has recognised the expertise that exists within our councils and our public health teams.”

An organogram of the service released in September showed that its top leadership included several senior figures brought in from retail, commerce and industry, but only one clinician in Susan Hopkins, an epidemiologist and Public Health England adviser on infection.

Former Sainsbury’s boss Mike Coupe was appointed as interim director of testing during the summer and Harding’s own adviser is a former TalkTalk employee.

Harding told MPs that external consultants had been used to set up the test and trace service because there were no permanent jobs when it was created.

She said: “We stood this service up in May at extraordinary speed, we built something that’s the same size of Asda in the course of five months. When you start something very quickly you need to pull on all the talents across all of society.

“You can’t offer people permanent jobs when you don’t have a permanent organisation, so you have to employ people either as independent individual consultants or through consultancy organisations.”

When asked if civil servants could have done the same job and if using the private sector was value for money, Baroness Harding added: “We need both.

“To stand a service up at this speed we have needed to call on the talents across the whole of society both the public sector and private sector, as the organisation becomes more established and more permanent we are able to offer people more long-term permanent jobs and we are seeing the proportion of civil servants grow.”

Reacting to her evidence, shadow health minister Justin Madders told HuffPost UK: “The poorly run, outsourced contact tracing system isn’t worthy of the NHS brand.

“Matt Hancock should put public health teams in charge of both contact tracing, and of mass testing from day one, to drive down infections and ensure this lockdown is as effective as possible in reducing the spread of the virus.”

During the committee session, Harding also admitted that test and trace had failed to anticipate the demand surge caused by the return of schools in September and said that insufficient financial support was a key reason for people not self-isolating.

Harding revealed that she had pushed ministers for more financial support for those who find it difficult to self-isolate for 14 days, a move that resulted in a £500 payment for the lowest paid.

When asked if even more cash support would help, she replied: “All the evidence shows that people are not complying with isolation not because they don’t want to, but because they find it very difficult.

“The need to keep earning and to be able to feed your family is a fundamental element of it, which is why I think the financial support payment is a very good thing.”

She said the actual sum of money on offer “was a decision for the government, for the prime minister and the chancellor”, not her.

She said preliminary data from the organisation’s own survey carried out from the end of August to mid-September showed “54% of people telling us that they didn’t leave home during the period that they were asked to isolate”.

Harding also acknowledged that the “balance between supply and the demand forecast” of Covid-19 testing towards the end of the summer “wasn’t right”.

Pushed on why the demand for testing was not anticipated when schools reopened, she said: “I said that we did not anticipate the exact amount, correct.

“With the benefit of hindsight, the balance between supply and the demand forecast wasn’t right, clearly that’s true.

“But what you’ve also seen in the last six weeks is that we’ve met our commitments to get that supply and demand into balance.”

Boris Johnson recently said for the first time that the test and trace performance on turnaround times and contact tracing had to get better. Harding conceded: “We have to keep expanding our testing, improving our tracing.”

Earlier in the evidence session, Sir John Bell, regius professor of medicine at Oxford University and a member of the government’s vaccine taskforce, said there was a “80%” chance of normality starting to resume after Easter provided “they don’t screw up the distribution of the vaccine”.