Where would Britain find eastern reinforcements?

Where could Britain obtain reinforcements for an eastern campaign despite pressure to send troops to France?

From forces released in Palestine, Persia, and other theaters once Ottoman defeat ended those campaigns.

The answer does not rely solely on creating new divisions in Britain. Once Ottoman resistance collapsed, forces committed in Palestine, Persia, and other imperial theaters could move toward the new eastern front. Their commanders would also bring experience from campaigning across the region. Gallipoli success could therefore condense several dispersed campaigns into a more concentrated coalition effort against Austria-Hungary and Germany.