If I had a business on the high street, I would be doing everything I could to ensure its existence. This would include giving out flyers (advertising my products/services), providing a better service than my competitors (local or otherwise), and delivering a product / service that is actually required at a price that my potential customers are willing to pay.

In short, I would take a more positive approach and give my customers reasons to support me rather negatively campaigning against a potential rival.

That said, I would have every right to raise my objections to any proposal not only as a local resident but as a local business to the appropriate authorities.