Scores of Portsmouth residents turned out to back a rally in support of saving the city's dockyard and the 940 BAE jobs there currently at risk.
The firm made an announcement earlier this week that it would begin closing the site next year. The proposal would see the end of centuries of shipbuilding in the city.
1800 jobs will be cut in shipyards operated by BAE Systems across England and Wales, bringing shipbuilding in Portsmouth to an end.
Unions are to meet defence giant BAe Systems to discuss the future of the firm's three shipyards amid a review of its business.