Failing to appoint a senior minister with sole responsibility over planning for pandemics and other threats has been an “error”, a former minister has said.

Sir Oliver Letwin told the official UK coronavirus inquiry on Tuesday that it is a “lasting regret” that he had not focused more on pandemics while in the Cabinet Office.

Labour said the admission is “too little, too late”, saying the Conservatives “cannot be trusted to protect the public from the emergencies of tomorrow”.

The minister, who has described himself as David Cameron’s “Mr Fix It”, said resilience only formed a “relatively small part” of his role despite it being in his brief between 2011 and 2016.

Instead he said he spent a lot of time on “endless discussions” with Liberal Democrat colleagues in coalition with the Tories in the “rather wide-ranging and unusual role”.

Sir Oliver said: “Actually there really ought to be a minister solely devoted to resilience at a senior level.”

Asked if anyone had ever had this role, he told the UK Covid-19 Inquiry: “There hasn’t as far as I’m aware, and I think that is an error.

“I came to that view very gradually but by the end of my time I was pretty convinced that we ought to have, and, had I remained in situ, I would’ve tried therefore to move to a model where somebody took that position.”

But appointing a junior minister would “achieve nothing”, he said, as they must be senior and close to the prime minister.

He expressed regret at following advice to focus on critical national infrastructure, which he described as “wildly under-resilient”, instead of pandemic flu, which he believed may have allowed him to identify “some other catastrophic pathogen” to prepare for.

“Actually, it is absolutely not an excuse for a minister, alas, because you can always ask the following question, you don’t have to accept the advice,” he said.

“That is actually what I should’ve done and it’s a matter of lasting regret that I didn’t.”

Sir Oliver also warned that the churn of ministers and officials tasked with preparing for emergencies is a “disaster for the country”.

He said there is an “overwhelming case” for training for ministers dealing with civil contingencies.

Shadow paymaster general Fleur Anderson said: “The Tories are showing that they cannot be trusted to protect the public from the emergencies of tomorrow. This Government has been asleep at the wheel for far too long.

“Oliver Letwin’s admission that there should have been a dedicated minister for resilience is too little, too late.”

George Osborne is due before the inquiry where he will face questions over how the austerity cuts he unleashed as Mr Cameron’s chancellor affected preparedness.