counter-proposal; alternative proposal
A formal proposal offered in response to or as an alternative to another proposal, often in business, politics, or negotiations.
The opposition party submitted a counter-proposal to the government's bill.
We explained our counter-proposal in response to the client's suggestion.
The opposition party put forward a counter-proposal to the government's plan.
If you're going to oppose it, you should present a concrete counter-proposal.
It's irresponsible to just criticize without offering a counter-proposal.
The committee chair asked the opposing side for a counter-proposal.