The MCC Cricket committee and MCC World Cricket committee both believe Test cricket should continue to be played over five days.
The ICC has raised the idea of Tests being shortened from five days to four but the MCC, following a recent meeting, has laid out their stance on the future of Test cricket.
A statement read: "MMC has noted the recent discussion regarding the future of Test cricket and the ICC's desire to debate the introduction of four-day Test cricket to replace the current five-day format in the World Test Championship from 2023.
"The MCC Cricket committee and MCC World Cricket committee have recently discussed the issue and although they can see some benefits that four-day Test cricket could bring, both committees believe that Test cricket should continue to be played over five days."
Five-day Tests have been set since 1979 and some of the format's most thrilling finishes – including the draw at the Oval which sealed England's historic 2005 Ashes win and the recent win over South Africa in Cape Town– have been played out on the final day.
The ICC, however, has permitted certain Tests since 2017 to be played over four days.
These matches are outside the World Test Championship, such as England's historic meeting with Ireland at Lord's in July.
Four-day Test matches would be likely to follow the playing conditions used for the handful of recent four-day Tests, with 98 overs scheduled for each day rather than 90.
But the MCC have joined the Federation of International Cricketers' Associations in backing the likes of England captain Joe Root and all-rounder Ben Stokes in calling for Test cricket to remain a format played over five days.
The FICA is the global players' representative body in cricket and has conducted extensive research on the matter among its membership.
FICA executive chairman Tony Irish stressed there was "currently a lot of negative sentiment" concerning the suggested proposed changes.