Anti-nuclear protestors demonstrated outside a Devon dockyard ahead of a Commons decision to approve updating the UK's Trident nuclear weapons.
Protesters handed leaflets to dockyard workers
Plymouth's Devonport Dockyard refits the current missile submarine fleet.
Protesters handed leaflets to dockyard workers and presented a mock Asbo to police and security staff at the yard.
Yard bosses and unions say a decision to replace the weapons system could mean long-term stability for it. MPs voted 409 to 161 to update the system.
The government plans to spend £20bn to replace the existing Vanguard fleet of four submarines which operate the Trident missiles.
It is estimated for every £1 spent on building a submarine, £3 is spent maintaining it throughout its service life.
Yard bosses said Trident refits would continue to pump more than £74m a year into the regional economy.
Devonport Management Ltd (DML) chief executive Dr Dennis Gilbert said: "In terms of employment, it's important; in terms of our skills and facilities, it's obviously important, and it forms an absolute bedrock of our business."
The Prospect union said it could also support Plymouth's case in the MoD's naval base review.
But members of the Trident Ploughshares protest group say this is not enough to warrant the new system.
Protester Shirley Law said: "Some people would say that we're wasting our time.
Devonport is the sole UK refitter for nuclear missile submarines
"At least if it does go ahead we can say that with our consciences we stood up and said 'No, the money could be used for better things'."
The existing refit work will begin to tail off within eight or nine years, but there could be more in the pipeline if the operational lives of the current submarines are extended.
It would take at least 17 years to design and build the new vessels. Defence Secretary Des Browne said recently he had not discounted the option of extending the life of the current vessels by 30 or 40 years.
Tony Blair tonight survived, with Tory support, a major Labour backbench revolt over renewing Trident.
After a bid to delay a decision - backed by Labour rebels and the Liberal Democrats - was defeated, the vote to actually update the system saw a majority of 248 as 409 MPs supported the proposals, and 161 said they were against.
The vote followed a six-hour debate and protests outside Parliament.
Mr Blair had said it was "essential" to renew Trident as soon as possible.