Mr Hancock believes the delay will ultimately cost jobs
The MP for Portsmouth South has given a cautious welcome to the news that the Navy's two new aircraft carriers will enter service later than planned.
Defence Secretary John Hutton said there would be no delay in construction - but work would continue at a slower pace, sustaining jobs for longer.
The £4bn project, partly based in the city, is due to start next spring.
Mike Hancock said: "On the question of it won't cost a single job, I think [Mr Hutton] might live to regret that."
"If there is a delay, certainly between the first construction and the second construction, I think it won't only cost more, I think inevitably it will cost jobs.
"I think Mr Hutton was a very brave man and I'm going to ask him in Parliament just how he can give such an assurance. I welcome it but I think he may live to regret it.
"The good news is the ships are going to continue to be built, that was the worry that one or the other or both were going to be pooled.
"What we've got now is the commitment that they will definitely be built.
"What I want to see is that first ship built to schedule and the second one not far behind. Any delay in between will bring doubts on the shipbuilding industry, not only here in Portsmouth, but elsewhere."