Steel company bosses will join thousands of steelworkers in a huge demonstration in Brussels on Monday calling for urgent action to help their crisis-hit industry.
Hundreds of workers from the UK will be among those pressing for the European Commission to tackle cheap Chinese steel being "dumped" across Europe.
Karl Koehler, chief executive of Tata Steel's European operations, will march alongside workers from his company's plants in the UK, including Port Talbot in south Wales where hundreds of jobs are being axed.
He said : "The situation facing Tata Steel and other European steelmakers is perilous.
"If the European Commission does not take immediate and robust action, thousands of jobs in the industry, and many more thousands in the wider supply chain, will be threatened.
"We are not asking for special treatment - we are asking for the European Commission to stand up for fair trade and to give European steelmakers a chance to compete on a level playing field. "
Business Minister Anna Soubry said: "We are taking action on energy costs, public procurement and industrial emissions at home to help the steel sector but this is a global problem requiring a global solution.
"This conference was convened thanks to UK efforts. We are working with other EU governments, industry leaders and trade unions to stress to the European Commission the need for swifter investigations into dumping and the tariffs then being set at the right level."
The Government said it was well aware of the challenges facing the steel industry and was working "tirelessly" to help.
GMB national officer Dave Hulse said: "The European Commission has done next to nothing to save steel jobs.
"The commission is now directly responsible for bringing more misery to an industry that has been rocked with job losses and communities being destroyed.
"We need the Prime Minister to get off the fence and forcefully tell Brussels that toothless action will do nothing whatsoever to assist the UK steel industry.
"For example the commission's own investigations of Chinese exports showed a dumping margin of more than 60% on reinforcement steel bar used in the construction industry."
Unite national officer Harish Patel said: "Government minsters need to start standing shoulder to shoulder with UK steelworkers by demanding swift action from the EU to stop the flood of cheap imports from China and other countries.
"Their refusal to back higher tariffs on cheap Chinese steel will be viewed as nothing short of a betrayal."
Roy Rickhuss, general secretary of Community, said: "Steelworkers across Europe are feeling the effects of unfairly traded imports and a lack of government action.
"Unions and businesses are joining together and with one voice demanding our governments back our steel industry."
GMB general secretary elect Tim Roache said he feared a meeting of the European Commission to discuss the crisis would be "another talking shop".
He added: "Since the problems in the steel industry became clear last September at Redcar, the Government has promised to deal with dumping from China but five months later no decisive action has been taken.
"The European Commission has done next to nothing to impose meaningful anti-dumping tariffs.
"The commission say that the biggest cheerleader for China to be awarded market economy status is the UK Government which would remove most powers to deal with dumping.
"The commission and the UK Government must change course and put saving the steel industry before sucking up to China."