LONDON, May 9 (Reuters) - Britain said on Saturday it was deploying its warship HMS Dragon to the Middle East in preparation for a potential multinational effort to protect shipping in the Strait of Hormuz once conditions allow.

HMS Dragon, an air defence destroyer, was sent to the Eastern Mediterranean in March, shortly after the start of the Iran war, to help defend Cyprus.

Its relocation to the Middle East follows a move by France to deploy its carrier strike group to the southern Red Sea, as the two countries work together on a defensive plan aimed at restoring confidence in the trade route.

"The pre-positioning of HMS Dragon is part of prudent planning that will ensure that the UK is ready, as part of a multinational coalitionjointly led by the UK and France, to secure the Strait, when conditions allow," a spokesperson for Britain's Ministry of Defence said.

As the U.S. and Iran inch toward a potential off-ramp from their 10-week war, France and Britain have been working on a proposal to lay the groundwork for safe transit through the Strait once the situation stabilises.

The plan would need coordination with Iran and a dozen countries have indicated a willingness to take part.

Britain's ability to participate in any protective mission will be limited by the stretched Royal Navy, which is much smaller now than in the past and which has had to retire some ships before replacements have become available.

(Reporting by Sarah YoungEditing by Alexandra Hudson)