George Osborne, Ed Balls and Danny Alexander will be quizzed by MPs on whether they would agree to a currency union with an independent Scotland as a "trade off" to keep the UK's nuclear deterrent on the Clyde.
Members of the Scottish Affairs Committee will also ask if a referendum would be required in the rest of the UK before a sterling zone could be created.
At the weekend an unnamed Coalition minister suggested the pro-Union parties' opposition to a currency union was a bluff.
The politician was quoted as saying "of course" there would be a decision to share the pound after independence, adding: "Saying no to a currency union is obviously a vital part of the No campaign. but everything would change if there were a Yes vote."
Ian Davidson, the Labour MP who chairs the committee, said: "The Conservative, Labour and Liberal Democratic parties have all said no to a currency union in the event of separation.
"The Scottish First Minister says they are all 'bluffing', which presumably is a euphemism for 'lying'.
"Are they all lying? Or are there sound and defensible economic and political reasons why a future UK Government , without Scotland, would want to avoid a currency union?
"An anonymous minister has suggested a trade-off with Trident. Is this on the table or will Trident will be looked at separately in a defence envelope with NATO, shipbuilding and other defence orders - or is no deal possible on Trident?"
SNP Westminster Leader Angus Robertson MP said: "The fact that the No campaign are digging themselves even further into this hole is great news for Yes.
"The No campaign has hit the panic button by calling in the Scottish Affairs Committee, and it doesn't matter what is said to the committee - that's the whole point of the damage done by the UK Government Minister who said there will be a currency union. As he or she admitted, what they say now is purely campaign talk to try to get a No vote, everything will change after a Yes vote and they will agree to share the pound.
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