Two men have been arrested after an amazing security breach in the House of Commons saw Tony Blair hit in the back by a missile containing a purple substance. MPs were showered by purple powder - later found to be coloured cornflour - which was hurled from a reserved area of the public gallery. No one was injured in the incident although Chancellor Gordon Brown also appeared to be struck by a similar missile. Health Secretary Dr John Reid reportedly breathed in a "lungfull" of the powder. Campaigning group Fathers 4 Justice - who demand equal rights for fathers -...