Viscount Alexander Newport, managing director of the Bradford Estates, said there is a "clear planning case" for the group's proposal to build 3,000 homes and commercial land off Junction 3 of the M54, near Tong.
His comments come after Peter Nutting, leader of Shropshire Council, this week revealed he had told West Midlands Mayor Andy Street, that his authority would reject the proposal when its cabinet meets next month.
The plan is unlike other Shropshire projects in that it has the support of the four Black Country councils which make up the Association of Black Country Authorities (ABCA).
They want the proposal to go ahead because it would contribute towards their own shortfall of space for homes.
In a letter to Shropshire Council last year ABCA said the homes represent a "once in a generation opportunity", and that it believed "exceptional circumstances" have been met to release the green belt land for development.
Lord Newport said they would continue to follow the planning process to get the project approved, despite Councillor Nutting's comments.
He said: “The J3 team has been left confused about the comments reported after the meeting. We’ve been engaged in detailed discussion with Shropshire Council’s planning officers over a two-year period.
“We believe there is a clear planning case to meet the county’s economic development aspirations at J3. This view has been endorsed by the ABCA in a letter which has been published in the press over the last couple of days.”
The proposals include 50 hectares of employment land, 3,000 homes, including a portion of affordable homes which Bradford Estates said would be "specifically designed with their surroundings in mind, as well as new schools, health provisions and a sustainable transport system".
Lord Newport said they see the plan as more than houses, and part of a unique and significant economic opportunity for the county.
He said: “The J3 development will be part of a joined up approach and future vision which would help both Shropshire and the wider West Midlands – it’s about far more than just providing new homes.
“The ABCA is right to say this is a ‘once in a generation opportunity’. There is a unique chance here to create a carefully considered development which would provide a real step change in economic opportunity for Shropshire as a whole and in addition help fulfil the duty of the county to assist its neighbours in meeting overall jobs and homes targets.
“These councils have a need which Bradford Estates has worked hard to see how we can accommodate, while at the same time making any development part of a wider progressive plan for the future of the estate itself.”
Clive Wright, chief executive of Shropshire Council, said no formal decisions have been taken at this stage and the authority could not comment further.
Bradford Estates is responsible for 12,000 acres of land on the Shropshire and Staffordshire border, which has been under the same family’s stewardship for 1,000 years.
The estate is currently home to a number of long-standing tenant farmers, businesses, residential properties, commercial units and 1,500 acres of managed woodlands.
Bradford Estates have urged anyone interested in speaking about the development to email firstname.lastname@example.org.