In a statement, Blair said: "Jack's contribution to law and order in Britain and this country's standing in the world is quite simply formidable.
"In 2015, Parliament will lose one of the most able politicians of my generation, but I have no doubt that he will be immensely successful in whatever he turns his hand to next."
More top news
Former foreign secretary David Miliband says he is 'deeply concerned' and refuses to rule out a future run for the Labour leadership.
By May, the supermarket's own brand chocolate products will be sourced ethically, meaning small-scale farmers will get a fair deal.
A group of anarchists have reportedly invaded a building metres away from the Queen's central London residence.