Dozens of locals descended on Tatton Community Centre in the borough, with many appearing to back a call from The Spinners landlord Glen Hutchinson for a rethink of how the Cowling Farm estate will be accessed.
Current proposals would see a new road for the residential part of the development cut straight through the existing pub car park.
Aaron Tilley, from consultancy firm Curtins, said there was an offer to provide a "like for like" replacement parking facility at the back of the pub - which would be completed before any spaces were lost.
But as observers looked on, Mr. Hutchinson claimed site plans showed that the new car park would be nearly 300 square metres smaller than the current one. And he added that a proposed on-street parking ban in front of the pub would further threaten his trade or lead to customers parking in nearby residential streets instead.
Chorley Council's director of development, Mark Lester, said the final design of the replacement car park would be determined by a "negotiation" with Homes England, the government agency which owns the part of the site where more than 150 houses are expected to be built.
Attention also focused on possible alternative access points - including a roundabout at the junction of Moorland Gate and Cowling Road, an option which had been discounted by Chorley Council.
Mark Lester told residents that cost was "not the only consideration" which had led to the decision. Highways bosses at Lancashire County have advised that the island would need to be 34m in diameter in order to accommodate the largest vehicles which may use it.
That would require a redesign of the road layout which would itself encroach on the pub car park and also come close to a decked area which the operators of The Spinners wanted to preserve.
But it was the removal of the roundabout option just before the consultation process opened - along with a second alternative for dual residential and business access from Moorland Gate - which sparked the liveliest exchanges at the event.
"Why change everything the day before?" Mr. Hutchinson asked. "People can only comment on what is put before them - and those options are not on the questionnaire."
Mr. Lester said that it was "coming through loud and clear" that some residents were not happy with the current proposals, which included a modified road design to protect the pub's decking.
"You need to feel what we have said tonight and take it back [to the council] and personally express that," another resident told him.
The current consultation is part of an informal process to gauge public opinion on a so-called "masterplan" for the development, which has been earmarked for housing and employment use since 2015. It will also provide the first permanent site for the travelling community in Chorley.
Speaking after the meeting, Mark Lester said Chorley Council and Homes England had chosen to engage with the public at an "early stage" and he encouraged residents to have their say on the options presented and "any alternative proposals they may have".
A second drop-in session will be held at the Tatton Community Centre on Thursday 8th November between 2.00pm and 5.30pm and locals can also submit their views via the planning portal on the Chorley Council website.
The formal planning application process is not expected to begin until the end of the year at the earliest, when there will be formal consultation on the details of the proposed development.