“The Fleet is now way below the critical mass required for the many tasks which could confront it, if the international scene continues to deteriorate.

“What remains of our surface Fleet now faces a prolonged period of uncertainty, as the frigate class is replaced in its entirety and all our destroyers undergo urgent, major remedial work on their unreliable engines.”

Dropping below the current 19 ships even for a short time would be "completely unacceptable" and leave the UK lacking the maritime strength to deal with the threats it faces from areas like Russia, the committee said.

"As an island nation, the importance of the Royal Navy to UK defence must not be underestimated," the committee said.

"Our starting point in this report is our conviction that the current number of frigates, destroyers and personnel inadequately reflects the potential threats and vulnerabilities facing the UK and its interests overseas."