Parties campaigning in the Dunfermline and West Fife by-election have voiced concern at the closure of the Lexmark printer plant in Rosyth.
Parties have called for action following the announcement
The Tories said it was a "hammer blow" for Fife's economy, while the Lib Dems promised to fight for new investment.
The Scottish Socialists called for a boycott of Lexmark products, while the SNP said an action plan was needed.
Labour said an "urgent" response was required and promised to continue fighting for new jobs.
Some 700 jobs will be lost with the closure of the factory, which has been based in the Fife town for a decade.
The Scottish National Party said 7,000 jobs had been lost in the region's manufacturing sector since 1988.
By-election candidate Douglas Chapman said an urgent action plan was needed to protect and attract jobs.
The party's Holyrood leader, Nicola Sturgeon, said: "This news is absolutely devastating for the people employed at Lexmark.
"Our thoughts are with their families at this very difficult time.
"It is an enormous blow to the local economy, which has already lost a lot of jobs and has a higher than average unemployment rate."
The Scottish Conservatives said it was the third announcement of major job losses this year in Scotland.
Shadow Scottish Secretary David Mundell MP said: "It is tragically and bitterly ironic that the day after Gordon Brown and Alistair Darling visit the area, the increasingly desperate plight of Scottish manufacturing is highlighted.
"The bulk of the blame here lies with the executive but we cannot overlook the role of the chancellor of the exchequer, and how he has failed to protect jobs in his own backyard."
The Liberal Democrats' by-election candidate Willie Rennie said: "Job losses of this scale are a major blow for the local community, but we must now focus on the future.
"It is important to keep these jobs and skills in the area and I am determined to fight for new investment and business for Dunfermline and West Fife.
"This news will come as a bitter pill to local people as these job losses come the day after the Labour Party boasted of its record on employment in Fife."
However, Scottish Secretary Alistair Darling said: "In the last eight years, 10,000 jobs have been created in Fife and our aim is to create 10,000 more in the next decade.
"This is exactly why the Dunfermline and West Fife by-election is about jobs and the economy."
He said an urgent response to the job losses was needed from everyone who could offer support on retraining, upskilling and employment opportunities.
John McAllion, who has been confirmed as the Scottish Socialist Party candidate, said he would be contacting trades unionists in an attempt to start a boycott of the company.
"Thousands of people in the region will suffer because of Lexmark's drive to increase their profits," he said.
"We are going to hit Lexmark where it hurts; in the balance sheets.
"I am calling on the people of Scotland to rally to the side of the Lexmark workers and boycott the company's products."
The National Alliance Against Tolls Scotland has named Tom Minogue as its candidate. NAAT Scotland said it would be concentrating on the issue of tolls on the Forth Road Bridge.
Ian Borland has been confirmed as the UK Independence Party's candidate.
The turnout for Dunfermline and Fife West at the last general election was 59.90%, with a Labour majority of 11,562.
The results were: Rachel Squire (Lab) 20,111 (47.44%); David Herbert (Lib Dem) 8,549 (20.17%); Douglas Chapman (SNP) 8,026 (18.93%); Roger Smillie (C) 4,376 (10.32%); Susan Archibald (Scottish Socialist Party) 689 (1.63%) and Ian Borland (UKIP) 643 (1.52%).