More than 100 angry residents packed a meeting to object to plans to redevelop Willen Village Centre.
The protesters, residents of Lovat Fields Extracare Village, met councillors and developers to voice concerns over the proposals and potential loss of the post office.
Councillor Ric Brackenbury explained residents were worried the size of a proposed new supermarket to replace the existing local store would threaten local services.
He said: “The size of the proposed new store would mean the current tentants would lose the right to operate it and this would likely lead to the closure of the post office as well as community outreach services to Lovat Fields and Oaktree Court in Willen.”
Developers told the meeting a larger supermarket was needed for commecial reasons. But residents, many of whom are elderly or have limited mobility, expressed concern over the potential loss of the community outreach programme as travelling to the local centre would prove difficult for them.
Mr Brackenbury agreed changes were needed but that residents’ concerns needed to be addressed before work could begin.
He added: “Willen Local Centre does need substantial work and several of the proposed changes will be beneficial.
“However, I’m concerned the removal of part of the service yard to make way for such a large store would put the post office and outreach programme to Lovat Fields Village and Oaktree Court at risk – and what this will mean for safe deliveries and parking.
“I hope the developer has now seen the role of the local store as part of the Willen community and can be persuaded to keep the size of the service yard as it is.”
The plans are expected to be heard by Milton Keynes Council planning committee this month.