An inquiry into the economic case for the £50 billion HS2 high-speed rail project - which will link London with Birmingham, Manchester and Leeds - is to be held by a House of Lords committee.
The Lords' Economic Affairs Committee has invited written submissions for its inquiry at a time when the HS2 Hybrid Bill has reached the committee stage in the House of Commons.
Questions the committee is seeking answers to include:
:: Is there an economic case for HS2?
:: Should the Department for Transport's strategic case for HS2 published in October 2013 have included any other factors in making an economic case for the project?
:: What are the likely economic benefits of HS2 to the Midlands, the north of England and to Scotland?
:: Will London be the main economic beneficiary of HS2? Might some areas of the country suffer economic disadvantage?
:: How should HS2 be operated? Should it be a franchise in competition with the West and East Coast Main Lines?
:: Should travellers pay higher fares on HS2 than other lines and does the prospect of HS3 (a proposed northern England rail scheme) affect the economic case for HS2?
The committee's chairman Lord Hollick said: "HS2 is likely to represent one of the biggest infrastructure investment programmes in the UK for decades.
"With over £50 billion of public money estimated to be spent it is vital that the public has confidence the project will produce real economic benefits."
He went on: "Our inquiry will attempt to get to the bottom of what the real economic impact of HS2 will be, who will benefit and who might lose out.
"We will find out whether the Government has taken full account of all the economic considerations in setting out the case for HS2 and what the impact will be in different parts of the UK."
The scope of the inquiry is limited to the economic case for the development of HS2. It will not cover aspects of planning or the impact of the Hybrid Bill on individuals with property on the proposed HS2 route.