Tatton Services would include a hotel and petrol station, as well as a shop and kitchen.
The proposed site – next to the M56 – is surrounded by the A556 and slip roads connecting the M56, A56 and A556.
Westmorland said it remained “steadfastly committed to the project” and would continue to “make the case” to the government.
“The proposed model will champion the farms and businesses who make local food and will create jobs and apprentice schemes for local people,” a spokesperson said.
A neighbouring local authority has withdrawn the objections it previously had to the proposed development.
A Trafford Council spokesperson told the Local Democracy Reporting Service it had originally voiced concerns about the green belt and the sustainability of the site.
But it said it had withdrawn its objection after Westmorland and National Highways said there was a “specific need” for a service station on the grounds of driver safety and welfare, especially for HGV drivers.
“This was the first time National Highways had indicated there was a specific need,” said Trafford Council. “Had they done so earlier, we would have had a different position on the proposal.
“In light of the late evidence, it is now our view that welfare and safety benefits outweigh the harm and we have therefore formally withdrawn our objection.”
The inquiry is due to run until 25 October.
