"This laser will be 200 times more powerful than the most powerful lasers that currently exist," said Professor John Collier, a scientific leader for the ELI project and director of the Central Laser Facility at the Rutherford Appleton Laboratory in Didcot, Oxfordshire.
"At this kind of intensity we start to get into unexplored territory as it is an area of physics that we have never been before."
The ELI Ultra-High Field laser is due to be complete by the end of the decade and will cost an estimated Â£1 billion. Although the location for the facility will not be decided until next year, the UK is among several European countries in the running to host it.
The European Commission has already this year approved plans to build three other lasers that will form part of the ELI project and will be prototypes for the Ultra-High Field laser.
Due to sited in the Czech Republic, Hungary and Romania, each laser will coast around Â£200 million and are scheduled to become operational in 2015.
The Ultra-High Field laser will be made up of 10 beams, each twice as powerful as the prototype lasers, allowing it to produce 200 petawatts of power â€“ more than 100,000 times the power of the world's combined electricity production â€“ for less than a trillionth of a second.
The huge amounts of energy needed to produce a laser beam of this strength is stored up over time before it is fired to produce large laser beams several feet wide that are then combined and focused down onto a tiny spot, much like sunlight through a magnifying glass.
At the focal point, the intensity of the light will produce conditions that are so extreme they do not exist even in the centre of our sun.
Dr Thomas Heinzl, an associate professor of theoretical physics at Plymouth University, said: "ELI is going to take us into an uncharted regime of physics. There could well be some surprises along the way."