 He struck a colourful and controversial figure in parliament and became renowned for his declamatory speech-making.He was a prominent obstructionist and claimed credit for inventing the tactic of obstructionism which was to yield such results for the Home Rule League under Charles Stewart Parnell.Indeed, O'Donnell saw himself as a natural leader and became disillusioned when Parnell was selected in May 1880 to succeed William Shaw as leader of the Irish Parliamentary Party.