Complex sentence: The DUP fought the resulting election to the Northern Ireland Legislative Assembly and took two seats in the multi-party power-sharing executive but while serving as ministers refused to sit in at meetings of the Executive Committee in protest at Sinn Féin's participation.
Split into simpler sentences: The DUP fought the resulting election to the Northern Ireland Legislative Assembly and took two seats in the multi-party power-sharing executive. While serving as ministers, they refused to sit in at meetings of the Executive Committee in protest at Sinn Féin's participation.