The facility could create around 1,500 jobs.
But Ms Leadbeater, who is Labour’s candidate in the forthcoming Batley and Spen by-election, has sympathised with residents and said much-loved green spaces should not be “traded” for jobs.
She described the warehouse, which will be a third of a kilometre long and eight storeys high, as “totally inappropriate”.
Opposition is growing against the 24-hour distribution centre, which is earmarked for 59 acres of fields between Whitehall Road, Whitechapel Road and the M62 and is close to housing, a horticultural nursery, a golf course and a cemetery.
Locals fear that the movement of between six and ten HGVs going in or out of the site every minute means local routes – including the A58 Halifax Road and the Chain Bar junction – could become clogged.
The facility will also have parking space for nearly 200 HGVs plus 900 cars and vans.
In her response to local campaigners Ms Leadbeater said: “I have been listening to your views and, as a local resident myself, I can understand why lots of people feel a building like this is totally inappropriate. I agree.
“As someone who has lived in this area all my life, like you, I really value the green spaces we all share and so have serious concerns about the potential development.
“If elected I have already made clear that one of my priorities will be to bring in good jobs for local people, but they need to be well-paid, quality jobs and we shouldn’t be in a position of trading jobs against our much-loved green spaces.
“I would also want to make sure any and all companies operating out of our area are paying their fair share in tax and contributing to the local community.
“It is absolutely essential that we prioritise ‘brownfield’ developments so we don’t spoil our countryside.
“In this case there must be other more suitable sites in need of regeneration as I will be having this conversation as a matter of urgency with the council.
“Most important of all, the people who live here must be consulted properly and be part of the decision-making.
“I have been informed that the process is at the very earliest stages and so I commit to working with local people to make sure your voices are heard, and that your objections carry weight as/if the proposals move forward.”
Plans for the scheme were outlined to members of Kirklees Council’s strategic planning committee last week.
However some members said they lacked detail.
A full planning application is likely to be brought forward in the coming weeks.
Comments made by committee chairman, Coun Steve Hall (Lab, Heckmondwike), who revealed he had known about the proposals for nine months, have also caused alarm.
One resident said: “I am concerned that a local Labour councillor has had knowledge of this development for nine months and appears to have been embargoed from letting local residents know the size of the development.”