Reports suggest the bulk of the cuts will be at Tata Steel's Scunthorpe site, which employs 4,000 people. However, the axe could also fall at sites in Clydebridge, Cambuslang, Dalzell and Motherwell.
The news broke as ministers, companies and unions held a crisis meeting in Rotherham over the UK's remaining steel industry.
It follows the closure of the UK's second largest steelmaker, SSI steelworks in Redcar, also announced this month. The liquidation will lead to 2,200 job losses and thousands more indirectly related to steelmaking.
"We’ll be seeking further discussions with Tata Steel to understand the full detail, examine alternatives that may safeguard jobs and uphold our principle of opposing compulsory redundancies," Roy Rickhuss, general secretary of Community, the steelworkers' union, said.
"This is yet another blow to our steel communities, demonstrates the precarious state of the UK steel industry and emphasises the need for government action, which Community and the employers have been calling for at the summit."
The UK steel industry has suffered as international competitors can manufacture steel at lower prices, at a time when global demand is also waning. Figures from World Steel have suggested global demand will remain muted, falling 1.7 per cent in 2015, with a 0.7 per cent rise in 2017.
Tata Steel declined to comment but said they've been making a number of structural changes to the UK business over the last months and years to make it more competitive.
"Like all companies we continue to review the performance of our business," he said, without addressing reports of job losses," a spokesman from Tata Steel added.