MPs will question how the contract for the controversial nuclear power plant Hinkley Point C was agreed this afternoon.
The Public Accounts Committee will quiz officials about the decision-making process and whether the project is good value for money.
It comes after the National Audit Office concluded in June this year that it will be impossible to tell for decades whether the station would be a good use of taxpayers' money.
In 2016 the estimated construction cost was £18 billion - but a year later the budget has risen to over £19billion.
Work is already well under way on the project.
Last month some workers on the project were told they will be balloted over strike action.