Sefton Central Labour MP Bill Esterson said residents of the borough have put up an "informed and considered" case against building on the greenbelt.
The deadline for submissions on the consultation of Sefton's Core Strategy was last Friday.
Bill Esterson said he received some fascinating reports from residents which gave reasoned arguments for preserving the area's greenbelt.
Bill said: "I think Sefton Council has been surprised by the sheers scale of opposition to building on the greenbelt in the borough.
"I personally received hundreds of submissions from people in all corners of the constituency rejecting proposals to build on greenbelt and greenspace in Sefton and thousands more have signed petitions.
"I went to many public meetings which were attended by hundreds of people throughout Sefton where one message was clear - no building on the greenbelt.
"I received very detailed reports from a number of people, most notably in Formby, Crosby, Maghull, Lydiate and Aintree which challenged many of the assumptions in the Core Strategy consultation document itself.
"They challenged the need for the number of houses required over the next 15 years and put the case for saving the greenbelt in Sefton for economic, environmental, agricultural and social reasons.
"Colin Reader of Maghull and Eric Haworth in Lydiate compiled independent studies of their own own and I'd like to applaud them for writing very detailed well informed and considered reports.
"What it shows is that we have professional people here in Sefton Central who have the expertise to aid local campaigns against government policy and in the community's interests."
Colin Reader told Bill Esterson that Sefton's Core Strategy document had failed to make the case for building on the greenbelt.
Colin said: "It is my view that Sefton is currently unable to present a sufficiently robust assessment with which to demonstrate the ‘exceptional circumstances’ required in order to release greenbelt land for development.
"When regeneration is factored in, the available numbers do not support the need for such additional urban expansion. Apart from the loss of productive and strategically important farmland, such proposals would increase the geographic area of the borough making the delivery of council services less efficient. To this would need to be added the substantial costs of extending existing infrastructure into what are currently rural areas.
"In addition, it is my view that Core Strategy Options 2 and 3 would be extremely bad for the Borough as they would direct investment towards the new centres of development, depriving the existing urban areas of the regeneration opportunities they so badly need.
"The only viable Core Strategy option is Option 1 however, this Option needs to be modified to include a very real undertaking by Sefton to engage with the most extensive remediation/regeneration agenda possible."
Bill Esterson said Sefton Council must now reconsider all of the options given the weight of public opinion against sacrificing greenbelt as well as the arguments put forward by residents.
Bill said: "All of our local experts agree, we need to preserve our greenbelt as an asset for the future - not have it concreted over.
"Now that the deadline for the consultation has been and gone, we must now work on forcing the Tory-Lib Dem government into making a u-turn on its plans to relax regulations for building on the greenbelt.
"The government’s planning reforms usher in a default ‘yes’ to development including on the greenbelt.
"What that means is that no matter what residents think as part of the Core Strategy in Sefton, developers will be able to swoop in and force through a planning application.
"Again by working together, we can force the Tories and Lib Dems in government into a u-turn on this ridiculous policy and safeguard our greenbelt and greenspaces for future generations."