Chancellor George Osborne says he believes the French government, which owns the energy firm EDF, is committed to building a new nuclear power station at Hinkley Point.
He was responding to MPs' questions after reports that the project, on the Somerset coast, could be further delayed due to financial and technical concerns.
On Monday the Financial Times reported that the final approval for the long-awaited Hinkley Point nuclear reactor in Somerset could be delayed by up to a year.
The French energy firm EDF has yet to make a final announcement on whether it will go ahead with the £18billion project, despite securing investment from China last year.
The decision could now be made in 2017, with reports that EDF are looking for more investors to help take on the debt.