A House of Lords committee will take evidence outside of Westminster for the first time when it comes to Scotland to consider the possible economic impact of independence.
The Lords Economics Affairs Committee will hear from politicians, academics and others during a special session in Edinburgh.
Former Chancellor Alistair Darling, leading the Better Together campaign that aims to keep Scotland in the United Kingdom, is among those giving evidence.
The committee will also hear from the leaders of the three main pro-Union parties in Scotland: Labour's Johann Lamont, Ruth Davidson of the Tories and Liberal Democrat Willie Rennie.
Patrick Harvie, whose Scottish Green Party recently voted to join the Yes Scotland campaign for independence, is also due to speak.
Others appearing are David Nish, chief executive of Standard Life, Professor Alex Kemp of Aberdeen University and Professor Charlie Jeffrey from the University of Edinburgh.
The committee is examining the economic implications for the UK of independence for Scotland.
It has been considering the matter since April, looking at issues such as how assets and liabilities such as North Sea oil and the national debt should be divided if Scotland left the UK.
They are also investigating the impact that independence could have on the Bank of England, as well as the possible consequences of an independent Scotland setting different tax rates from the rest of the UK.