In September 1914, just as the First World War broke out, the UK Parliament passed the Third Home Rule Act to establish self-government for Ireland, but was suspended for the duration of the war. To ensure implementation of Home Rule after the war, nationalist leaders and the IPP under Redmond supported with Ireland's participation in the British and Allied war effort under the Triple Entente against the expansion of Central Powers. The core of the Irish Volunteers were against this decision, but the majority left to form the National Volunteers who enlisted in Irish regiments of the New British Army, the 10th and 16th (Irish) Divisions, their Northern counterparts in the 36th (Ulster) Division.