 He publicly supported Sinn Féin and the unification of Ireland , although in 2005 he suggested to Sinn Féin leaders that it abandon its long @-@ standing policy of not taking seats at Westminster ( abstentionism ) . Sinn Féin in turn argued that to do so would recognise Britain 's claim over Northern Ireland , and the Sinn Féin constitution prevented its elected members from taking their seats in any British @-@ created institution . A supporter of the Scottish Parliament and political devolution , Benn however opposed the Scottish National Party and Scottish independence , saying : " I think nationalism is a mistake . And I am half Scots and feel it would divide me in half with a knife . The thought that my mother would suddenly be a foreigner would upset me very much . " 
