1987 files: Government wanted to shut down Harland and Wolff shipyard, but Tom King warned Thatcher it would wreck peace
Shutting down Harland and Wolff in the 1980s risked throwing the peace process into turmoil, civil servants warned.
They feared closure would mean violent opposition and a "serious" blow to political progress.
One memo warned of protests on the scale of those which followed the 1985 Anglo-Irish Agreement.
The situation was so grave, Secretary of State Tom King briefed the Prime Minister on the "very major" political implications.
Once one of the world's largest shipbuilders, Harland and Wolff built more than 70 ships for the White Star Line, including The Titanic. By the 1980s, the company was struggling to stay afloat.
It was receiving £30m a year in Government aid and officials said closure would be a cheaper option.
A 1985 corporate plan calculated that its order book would run out by the end of 1986.
Yet it remained Northern Ireland's second largest manufacturing employer, providing work for around 4,800. Staff were from largely Protestant east Belfast.
By September 1987 a decision had been taken to close the shipyard after the completion of a contract for an auxiliary oiler replenisher (AOR) vessel.
However, a memo to the Secretary of State warned of serious political and security implications.
The document, written by FG McConnell, said: "It is thought that, within the loyalist community, reaction, particularly in east Belfast, would be along the lines of the opposition which followed the signing of the Anglo-Irish Agreement. Like the Agreement, the closure of H&W would be perceived as an act of betrayal by HMG and a further step towards withdrawal from the province."
The memo warned that the mood would be exploited by loyalist paramilitaries.
By November 1987 the Secretary of State had reluctantly signed off the decision to close Harland and Wolff after the completion of the AOR vessel. It would be announced at the same time as the break-up and denationalisation of British Shipbuilders.
But in a letter to Margaret Thatcher, Mr King said closing Harland and Wolff would cause more difficulties than elsewhere.
In 1989 Harland and Wolff was bought from the Government in a management/employee buy-out in partnership with the Norwegian shipping magnate Fred Olsen, leading to a new company called Harland & Wolff Holdings Plc.
By this time, the number of people employed had fallen to around 3,000.