Critics say efforts to rescue the animal, nicknamed Timmy, unlikely to succeed and could lead to further harm

A last-ditch effort to rescue a wayward whale that has transfixed Germans for weeks has begun in the Baltic Sea despite criticism it has little chance of success and could further harm the 12-tonne creature.

The male humpback whale was first spotted last month near Timmendorfer Strand on the northern coast of Germany, giving rise to its nickname Timmy. It has repeatedly become stranded and then freed itself after human assistance but it is now stranded again, with rescuers saying it is fighting a losing battle for its life.