GLASGOW will reap the benefit of hundreds of millions of pounds investment if a new 'frigate factory' is built at Scotstoun, it was claimed today
But it would signal the end of shipbuilding in Govan.
Glasgow MP John Robertson is the first major Westminster figure to back the scheme - and the first to begin hinting at the sheer scale of work that will be needed north of the river.
The Labour MP's remarks came after BAE Systems, which runs both Scotstoun and Govan yards, entered formal planning consultations on two options for building a new generation of frigates, Type 26, for the MoD.
The first is to build the so-called Global Combat Ships across both Clyde yards.
The second is to focus entirely on upgrading Scotstoun.
That would mean current orders for smaller patrol vessels, announced in November, would be carried out at Govan while Scotstoun was renovated.
Mr Robertson said: "Let's look at both options.
"Firstly, both Govan and Scotstoun could stay open, with jobs and work for, hopefully, the foreseeable future.
"Or, secondly, we could set up the Clyde to be a state-of-the-art shipyard that could compete internationally.
"There would be a financial impact from going for the latter option.
"It would take hundreds of millions of pounds to rebuild the old yard at Scotstoun and bring it up to the standard required.
"The down side would be the closure of Govan, although it would pick up work from Scotstoun while it was being renovated.
"My favoured option is to do what would be best for the long term future of the Clyde and spend hundreds of millions of pounds at Scotstoun and secure shipbuilding in Scotland for much of the rest of the century."
Gordon Matheson, Labour leader of Glasgow City Council - which has been in consultations with BAE over planning developments - has already signalled he would accept the closure of Govan if unions were happy with the deal.
Crucially, the exact configuration of how the frigates are built should not impact on the number of jobs.
BAE insists it has made no final decision on the future of its two Clyde yards - just two months after announcing more than 1700 job losses, around 800 in Scotland, as it winds down from its current aircraft carrier orders.
The company has been tipped to prefer the Scotstoun-only option, shutting the historic Fairfields site at Govan.
Some city insiders believe this could free up the old Govan yard for some other kind of development, from housing (it is opposite the Glasgow Harbour development) to industrial (it remains a good site for work on, for example, renewables).
However, the totemic status of Govan - workers joke the yard has nine lives - means few politicians have been prepared to speculate about it closing.
BAE began to explain its decision making process to workers last month.
At the time a company spokeswoman said: "No decisions have been made and the discussions are part of our ongoing consultation.
"Our aim is to create a world-class warship design, build and integration capability, ensuring that we deliver value for money."
BAE is intimately involved in preparations to build the new Type 26s and is the only manufacturer of warships in the UK.
It currently has three yards.
They are the two Glasgow ones, and a smaller new one in Portsmouth that it slated for closure in November after having to pay huge compensation to a foreign navy after a contract fell through.
The company's Type 26 contract has become highly controversial thanks to the Scottish independence referendum.
Campaigners in Portsmouth want to see the contract brought to them if Scots vote 'yes' this September.
Industry insiders stress this would be a hugely expensive and impractical option.
However, unionist politicians warn that a future English navy may well choose to build new ships its own territory.
Mr Robertson said: "The Type 26 contracts will not be awarded until the referendum has taken place. Is that a coincidence? I don't think so."
The Scottish Government, meantime, has also signalled it would be interested in ordering Type 26s for an independent navy.
Neither government has settled exactly how many ships it would need.