A decision over the future of Port Talbot steelworks in south Wales could be made in just over a week.
Sky News understands that a meeting of the Tata Steel board in India will take place on 29 March.
Sources told Sky they fear that the outcome "won't be the best decision for Port Talbot" and could result in the partial or full closure of the plant.
In January, Tata announced the loss of 750 jobs at its site in Port Talbot which it later reduced to 726.
Sky sources suggest that initially it was understood that the Indian board would be presented with a rescue plan aimed at turning the plant around so that in two years it was making £100m a year profit rather than a £200m loss.
This would have been coupled with a £100m investment from the Indian board.
However, Sky News understands that sources on the site have raised concerns that instead the board will be presented with an unachievable plan which would mean the plant would have to turn itself around in one year.
They fear this will be rejected and the hoped-for investment will be withdrawn.
It is believed that over the next week efforts will continue in earnest to persuade the board to consider the original two-year rescue plan.
A spokesperson for Tata said it was aware of the speculation but did not wish to comment.
Steelworkers' union Community said it had held an urgent meeting with Tata Steel's Europe boss Hans Fischer..
Community general secretary Roy Rickhuss said: "Today's meeting reaffirmed the joint desire of Community and Tata Steel's UK leadership to save the Port Talbot steelworks.
"The turnaround plan, which included over 1,000 job losses, has been tough to accept, but we are determined to make it work for the future of our industry.
"Reports that suggest the Tata board in India will reject this turnaround plan are deeply concerning and Community will be doing all we can to ensure the company do not go down this route.
"The workers at Port Talbot have achieved everything asked of them and deserve the continued support of Tata."
Tata cut 1,200 jobs at its sites in Scunthorpe and Lanarkshire in October 2015.
The UK steel sector is seeing large scale job losses as it buckles under pressure from cheap Chinese imports which are pushing European prices down.
At the time of the announcement of more than 700 job losses at the Welsh plant in January, Stuart Wilkie, director of Strip Products UK, said: "We have to accelerate the changes we announced last August, by lowering our costs at the same time as focusing on manufacturing higher-value products.
"These are urgent steps needed to give this business a chance of survival."
The steelworks at Port Talbot currently employs around 4,000 people as well as 3,500 contractors.
Source: News.Sky