Thousands of highly vulnerable people are at risk during lockdown amid a lack of government clarity over how to feed them, the UK's largest council warns.
Birmingham's fears focus on the "shielded vulnerable" - those advised not to go out in any circumstances during the Covid-19 pandemic.
The council says mixed messages over getting food to their door compromises the help it can offer them and others.
The government said it had "acted urgently" in the pandemic "crisis".
According to the council, however, the government has also acted with ambiguity over how the authority should be supplying and funding food for the "shielded".
In a letter to the local government secretary, leader of the Labour-run council Ian Ward said the situation was compounding an existing financial headache.
A £38.7m slice of central cash to help the authority meet wider social challenges during the pandemic has already been spent twice over, the letter states.
The "shielded vulnerable" - about 900,000 people across the UK - are those with pre-existing health conditions, including transplant recipients and patients with certain types of cancer.
They are deemed to be at particular risk from Covid-19, and guidance for them is stiffer accordingly.
Under national plans, the government is to organise the supply of food parcels directly to their door.
But before full roll-out in Birmingham, the council had been preparing a strategy to cover the interim period, which was based, Mr Ward said, on government guidance.
It was there, he said, that contradictions had arisen which meant "lives are being put at risk".
According to the correspondence, food had been due from the government on 28 March, with the council putting in place infrastructure for onward delivery, anticipating this "drop-off would be the first of a number of waves of supplies to be made by government".
But Mr Ward said not only did the drop happen six days later, it came with news this would be the only time food would be sent to the council for passing on to the "shielded".
Mr Ward said "a total lack of clarity" from the government "makes it impossible for us to plan effectively, at a time when our resources are already stretched in dealing with the emergency".
He is seeking guidance about how long the interim period will last and how the council will fund food distribution for the "shielded" in the meantime, on top of other social care commitments.
A government spokesperson said: "The government has acted urgently to tackle this public health crisis.
"We're working with the groceries industry, local government, local resilience and emergency partners to ensure essential items are delivered directly to the homes of extremely medically vulnerable people, at the highest risk from coronavirus."
Mr Ward says an exacerbating factor is not knowing how many "shielded" people there are in Birmingham. He has demanded a finalised list.
He has, however, received from acute NHS providers details of more than 3,600 people, along with two other lists with "several thousand names".
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