The Health Secretary has defended plans to break up England’s public health body in the middle of the coronavirus pandemic.

Critics have expressed dismay that Public Health England (PHE) was being dismantled during the crisis, with some calling the move “risky” and “irresponsible”, but Matt Hancock said delaying the change would have been “wrong”.

On Tuesday he announced the Government was pressing ahead with controversial plans to scrap PHE.

The new National Institute for Health Protection (NIHP) will take in some of PHE’s responsibilities along with the NHS Test and Trace programme and the work of the Joint Biosecurity Centre.

The organisation, headed by Tory peer Dido Harding, will respond to health threats including infectious diseases, pandemics and biological weapons, he said.

In other developments:

– Heathrow Airport announced the development of a new coronavirus testing facility it hopes will lead to the end of the mandatory 14-day quarantine for people returning from certain countries, and to “protect the economy”.

– Health officials announced plans to ramp up the coronavirus infection survey across Britain. The Office for National Statistics research aims to increase to include 400,000 people – up from the current 28,000.

– Data from official agencies across Britain show that more than 57,000 deaths involving Covid-19 have been registered in the UK.

Mr Hancock, quizzed about the timing of the PHE announcement, told Sky News: “My responsibility is to make sure that the pandemic response is the best it possibly can be and that’s why I’ve taken this decision now.

“One of the lessons from the crisis, for me, is that if something is the right thing to do, then delaying doing it is the wrong thing.

“I think PHE have done an incredible amount of work during this crisis – their science has been some of the best that’s been done anywhere. They were one of the first to come up with a test of coronavirus and to sequence the genome. And I want to put on the record my thanks for the work that they’ve done.

“But we’ve now got Public Health England, we’ve got NHS Test and Trace, we’ve got a new Joint Biosecurity Centre working separately.

“And so in order to keep people safe and in order to have the very best possible response that we can, we need to bring these organisations together now.

“We’re going to do this carefully. I entirely understand concerns, but on the other hand, all my experience through this pandemic has told me that if you need to act, you need to get on with it.

“And I hope that this gives a long-term future for all those working on the pandemic response.”

I don’t accept that there will be disruption. And the reason is we are bringing together under a single leadership these functions

He denied that the structural reorganisation would cause disruption.

He told BBC Radio 4’s Today programme: “I don’t accept that there will be disruption. And the reason is we are bringing together under a single leadership these functions.”

Pressed on people working at PHE being concerned about jobs, he said: “No, I don’t accept that. In fact we’re putting more support in and we’re hiring and the budget is going up enormously.”

On the appointment of former TalkTalk boss Baroness Harding as interim executive chairwoman of the NIHP, he told LBC: “Anybody with enormous experience like Baroness Harding will have had to face challenges in their professional career.

“I think having somebody with enormous experience, both running very large organisations in the private sector and as the chair of the board of NHS Improvement the last three and a half years, she has what it takes to lead this organisation, to get it set up.

“The key thing now is to make sure that there is a seamless impact on the coronavirus response, actually that that is strengthened, and I think her leadership will be an important part in that.

“Ultimately it is ministers who are responsible for all decisions that governments make. That’s why I come on the radio to talk to you and answer questions, and am accountable in Parliament.

“The whole media discussion around this about ‘who is responsible?’ I think is frustrating because, frankly, I am responsible for what happens in the health and social care areas. Of course I am.”

Labour said breaking up PHE in the middle of the pandemic was “irresponsible” and “risky”.

Undoubtedly, there are questions to be answered about England's handling of the Covid-19 crisis, but the middle of a pandemic is not the time to dismantle England's public health agency

Shadow health secretary Jonathon Ashworth added that structural reorganisation is “time consuming and energy sapping”.

Richard Murray of the King’s Fund said: “Undoubtedly, there are questions to be answered about England’s handling of the Covid-19 crisis, but the middle of a pandemic is not the time to dismantle England’s public health agency.”

Nigel Edwards, chief executive of the Nuffield Trust think tank, said: “The Government risks making a major misstep by dismantling its own public health agency at such a crucial time, creating a huge distraction for staff who should be dedicating themselves to the next stage of the pandemic.”

Christina Marriott, chief executive of the Royal Society of Public Health, said: “We question the timing of an announcement to scrap our national public health agency in the midst of a global pandemic and before any public inquiry any has started, let alone reported.”

Jeanelle de Gruchy, president of the Association of Directors of Public Health, said: “The timing of this announcement risks distracting efforts and throws roles, functions and leadership into uncertainty.”