Planning officers are recommending the scheme, which is backed by the Yorkshire Agricultural Society (YAS), be turned down when it comes before the committee next Tuesday.
Although the planners have no complaints over the design of the 'showcase' project - the first phase of a larger five-year development programme, which includes a new exhibition hall and hotel - the authority is worried about the economic impact of the scheme on the city's existing shops.
According to the report, the agricultural centre's farm shop and café would be built in an 'unsustainable location' and would contravene PPS6 planning policy.
However YAS's chief executive Nigel Pulling, who picked the large Yorkshire-based practice's scheme ahead of five others more than a year ago, thinks the planning officers have got it wrong.
He said: 'Every time the planners had the chance of seeing the bigger picture they looked at the narrow interpretation.
'If this was a Tesco, I could understand their attitude, but it is in essence a high-quality, sustainable farm shop and we are rather proud of the designs.'
Pulling is determined to press on with the scheme even if the committee refuses to grant permission . He added: 'This is a key part of our strategic plan and we will certainly battle on. It is too important not to.'