The House of Lords rejected a change to catering arrangements to save taxpayer money because they feared the quality of the champagne would suffer.
Sir Malcolm Jack, clerk of the Commons between 2006 and 2011, disclosed the revelation to a stunned government committee tasked with examining how Westminster is run.
The Chair, Jack Straw, said: "“Did you make that up? Is that true?" Jack replied: "Yes it is true."
Despite the two Houses already sharing IT and cleaning contracts, Peers objected merging catering facilities with the House of Commons in case they were forced to drink cheap sparkling wine.
Further evidence of the Lords' attitude to their champagne came in evidence given by retired clerk of the house, Sir Robert Rogers, the next day.
When asked about the failure to merge catering services he said: "It would be very difficult to get a joint catering service. I must be very careful for a number of reasons what I say here."
Straw replied: "The champagne? We heard a few things yesterday."
Rogers said: "No, I am not going into the quality of the champagne. People are very possessive about some services. Catering is an absolute classic."
An Freedom of Information request by the Huffington Post revealed in May of this year that the House of Lords had bought the equivalent of five bottles of Champagne per peer per year since 2010.
House of Lords officials spent just over a quarter of a million pounds (£265,770) topping up their champagne stocks since May 2010 to March 2014, which peers and their staff could enjoy in the parliamentary dining rooms, bars, banqueting facilities or buy at the gift shop.
The 17,424 bottles bought over this period at the taxpayer's expense could give each peer 22 bottles of bubbly each.
As of 31 March this year, the House of Lords, which currently has 780 peers, had 380 bottles of champagne in stock, worth £5,713, held in its main cellar and at individual stores on site.
Officials bought in 4,691 bottles in 2010, with the number rising by over 1,000 each year to finally reach 8,082 in 2013, a 72% rise. The House of Commons has a total of £41,077.51 of wine and champagne in its stocks, according to the figures.Suggest a correction