nail one's colours to the mast

Alternative forms

 * pin one's colours to the mast

Etymology
From the naval military practice of displaying one's colours (signal flags or insignia) from the mast of a ship during battle to show loyalty. To surrender, one would strike one's colours, i.e. take down one's flag. If a ship nailed its colours to the mast, it would fight to the death and not surrender.

Verb

 * 1) To clearly show one's support for a side or opinion in a dispute, often indicating an intention to defend that side to the end.

Translations

 * Finnish: liputtaa ... puolesta
 * German:, hartnäckig aushalten, nicht kapitulieren
 * Polish: obnosić się ze swoimi poglądami