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.
Work has begun in Portsmouth on a key section of a new aircraft carrier.
More than 100 engineering jobs have been protected in Portsmouth thanks to a £70 million contract to support the Royal Navy's fleet of warships.
The two and a half year contract means staff at BAE Systems will be needed to maintain six Type 45 Destroyers.
The contract will ensure the warships are fit to operate effectively around the world.
Minister for Defence Equipment, Support and Technology Philip Dunne MP said, "This £70 million contract is good news for Portsmouth. It will protect the skills of around 100 expert engineers and makes clear that the future of the city's ship support industry is bright."
MPs have called for a new £200m research ship to be built in Portsmouth.
The bid comes after 900 jobs were cut when BAE Systems stopped operating at the historic shipyard.
Chancellor George Osbourne announced that the Government will fund the new vessel which could help replace Britain's two current polar exploration ships.
The pioneering ship will have on-board laboratories and robotic submarines to gather marine biology data.
Portsmouth South's MP, Mike Hancock, has written to the Business secretary, Vince Cable, asking to ensure the contract is given to Portsmouth.
Penny Mordaunt, an MP for Portsmouth North, has also asked for a meeting with the Chancellor about the proposal.
"The timetable of this suits us well because they will be putting this out to tender now and the ship would be in its trials in 2018 - we are looking at moving very quickly on this. It is clearly the sort of ship that our local workforce is all about."
The Prime Minister has pledged his support to the people of Portsmouth, saying his government will do all it can to win new business for the city
More than 900 BAE workers will lose their jobs when work on the £800 million aircraft carriers move to Scotland.
In an open letter, David Cameron says his Government will do all it can to help win new business.
David Cameron has written an open letter to the people of Portsmouth pledginghis support after last year's announcement that shipbuilding will cease in the city. In November, BAE announced more than 1,000 job losses when its current work to build the next generation of aircraft carriers finishes.
In the letter, he said the cost of BAE continuing to build ships in the city was "unaffordable" but his Government would do everything in its power to help win new business for the south coast city.
David Cameron wrote: "For centuries shipbuilding in Portsmouth has been woven into thehistory of Britain. It is a tradition of which the whole country is rightly proud - and Icompletely understand the intensity of feeling here is stronger still.
I make this pledge to you today: this government will do everything we can to protect the future of the shipyard and the livelihoods of the people who work there. In the months ahead we are going to go all out to make sure that it remains strong, successful, and respected around the world."
British defence giant BAE Systems is to recruit 568 apprentices in 2014, including around 100 who will join shipbuilding and maintenance teams in Portsmouth and Glasgow. Positions start in September 2014 for 42 months, with an average salary of around £14,000 and a guaranteed job at the end.
The defence contractor and the Ministry of Defence hope the scheme will offset the effects of 940 BAE job cuts at Portsmouth dockyard announced earlier this year. More than half of the new 568 apprenticeships will be at a submarine yard in Barrow-in-Furness.
BAE Systems first caused controversy when it announced severe job losses at Portsmouth shipyard, but now it has announced it will recruit apprentices in 2014 to build new submarines.
The Government-backed scheme will take on 181 more people than last year across its 16 sites as the company races to meet what it calls 'the largest workload for two decades'
Positions start in September 2014 and last 42 months, with an average salary of around £14,000 and a guaranteed job at the end.
100 apprenticeships will join shipbuilding and maintenance teams in Portsmouth and Glasgow, while 94 apprentices will design and build military aircraft in Lancashire and Yorkshire.
Portsmouth City Council is fighting to keep shipbuilding in the city by backing an online petition.
BAE Systems announced the end of shipbuilding in Portsmouth with the loss of 940 jobs. Protestors say another 2,000 jobs in the area could be lost from suppliers who are dependent on the shipyard.
Cllr Vernon-Jackson is forming a task group to tackle the consequences of the shipbuilding decision, and local leaders have also asked for government support for this.
– Cllr Gerald Vernon-Jackson, Leader of the Council
I talked to Dr Cable about the shipyard issue and what we can do to try to protect jobs. One idea I want the government to consider is that one of the Royal Navy's three new offshore patrol vessels could be built in Portsmouth.
A petition calling for the retention of skilled workers in the Portsmouth Naval Base following the closure of BAE Systems’ shipbuilding site has been started by Portsmouth Labour group.
It reads "I support the protection of high-skilled jobs in Portsmouth and demand that the council and its partners in government work with all parties to protect the long-term future of Portsmouth Dockyard.”
It is available online and signatures are also being gathered on the doorstep.
John Ferrett, the Leader of the Labour Group on Portsmouth City Council and the Parliamentary Candidate for Portsmouth North, believes the closure means vital skills will be lost at the Naval Base.
He has criticised the MP for Portsmouth North, Penny Mordaunt, for her stance on the closure.
– John Ferrett, Portsmouth Labour
It is astonishing that the MP for Portsmouth North is supporting the closure of the shipbuilding facility in Portsmouth. Workers need the support of their elected representatives at a time like this.
Furthermore, Portsmouth Naval Base will be the home of the two new aircraft carriers and there will be a demand for skilled labour when they come to the city in the second half of the decade.
It seems madness to lay off nearly a thousand skilled workers when their skills will be in demand in the near future."
Unions are due to meet bosses at BAE Systems today to fight plans to cut 940 jobs in Portsmouth.
Five centuries of shipbuilding will stop in the city from next year.
Work on the new eight hundred million pound aircraft carriers will move to Scotland - but the ships will be based in Portsmouth, with workers maintaining them.
Hundreds of people have been taking part in a rally in Portsmouth - to demonstrate against the planned closure of the city's shipyard. BAE Systems announced the move earlier this week, meaning more than nine hundred people will lose their jobs. Richard Slee reports.