Councillor Shaun Davies, leader of Telford & Wrekin Council, said the coronavirus had left a £10 billion 'black hole' in local government finance across England.
He said unless the Government stepped in to plug the shortfall, this would mean a likely £3.5 billion cuts to adult social care budgets this year – equivalent to 176,000 long-term adult social care places for over-65s and 23,000 short-term places.
Councillor Davies said if the Government did not honour its pledge to do 'whatever it takes', 100,905 adult social care places would go in the West Midlands alone.
He described the figures as 'terrifying'.
"Everyone in this community knows the sacrifice and the loss we have endured through the coronavirus crisis, and we all know the enormous strain on our carers, and our friends and family who rely on their care," said Councillor Davies.
"It is beyond belief that the Government is not standing by them in their hour of need."
Councillor Andy Burford, cabinet member for health and social care at the Labour-run authority, said the loss of so many places would be devastating.
"We will do whatever we can to shield those most in need from these cuts, but the reality is that if ministers don’t fulfil their promise and close the £10 billion funding gap then frontline services will bear the brunt and our community will suffer.”
Shadow communities secretary Steve Reed said ministers, including Health Secretary Matt Hancock and Communities Secretary Robert Jenrick, had promised to 'do whatever it takes' to ensure local councils had the funding they needed.
But he accused Mr Jenrick of 'rowing back' on that commitment, telling MPs that councils should not 'labour under the misapprehension' that all their costs would be reimbursed.
He said that local councils had estimated they would need approximately £13 billion to cover their losses, as a result of extra costs and lost revenue due to the coronavirus outbreak.
But he said so far the Government had only provided £3.2 billion towards the cost, leaving a near-£10 billion shortfall.