Plans for a new Tesco in Stanmore received a mixed reaction from residents and shopkeepers.
Spenhill, a subsidary of Tesco, is hoping to build the store in The Broadway, along with 65 new homes, a cafe and a library.
The company held a public exhibition to get residents' opinions on their plans last weekend.
Tony Raymond, the chairman of the Stanmore Society, believes the development is unnecessary as the area already has a Sainsbury's, in The Broadway and a Lidl.
He said: " I think it should be stopped in its tracks. It will put pressure on an already overburdened traffic system, it is already difficult to get through the Broadway at times."
Resident Velma Forsyth, of Rainsford Close, said: "I think it would be good for the area, as long as it is done right and it is not densely populated."
Spenhill and Tesco currently own the site of Stanmore library, in Stanmore Hill, which they lease to Harrow Council.
However, it would need to acquire the site of a former multi-storey car park next to Lidl, behind The Broadway, from Harrow Council in order to progress with its plans. If the new complex was approved it would mean that Stanmore library would be demolished, along with Anmer lodge, a homeless shelter.
James Wiggam, corporate affairs manager at Tesco, said: "We are having the consultation to get local views and what people think about the proposals. We saw an exciting opportunity in Stanmore and we only develop where we feel there is demand."
The planned store, which will be 20,000 sq ft, will boast a 400-space car park. The company claims it would re-house residents of Anmer Lodge, in Coverdale Close, within the new site.
However small local shops are worried that the proposed development will take business away from them. Kiran Bhudia, owner of Pooles newsagent, in The Broadway, said: "If they go ahead with it will kill the high street. We have two supermarkets, what do we need a third one for?"
Tesco and Spenhill will now have to apply for planning permission from Harrow Council.
Councillor Marilyn Ashton, portfolio holder for planning, development and enterprise said: "It is a matter for Tesco if they wish to hold a private exhibition at the Bernay's Memorial Hall and there is no partnership, agreement or commercial arrangement between Tesco and the Harrow Council.
"Furthermore and for the avoidance of doubt, the building in which Stanmore Library is located, for which the Council pays rent, has been privately owned for more than two decades so it is also a private matter for Tesco that they have purchased the freehold from the owners."