Guardian: An extra £800m is to be pumped into Britain’s new high-speed rail network as ministers face down Tory MPs threatening to rebel against plans to drive the line through the picturesque Chilterns. In contrast to Margaret Thatcher, who insisted the Channel tunnel had to be built with private capital, the Tories will declare that the state will bear the burden of funding the network. David Cameron, who signed up two years ago to a high-speed rail network from London to the north of …