LONDON - Britain’s government on Tuesday approved the construction of a high speed rail network linking London with cities in central and northern England from 2026 at a cost of almost £33 billion. Supporters of High Speed 2, which will see journey times between London and Britain’s second biggest city Birmingham slashed to 49 minutes from around 1.5 hours now, say it will boost Britain’s economy in both the short and long term. Opponents argue it is too expensive and that building a new rail line carrying trains travelling 225 miles (360 kilometres) per hour will scar England’s countryside. “I have decided Britain should embark upon the most significant transport infrastructure project since the building of the motorways by supporting the development and delivery of a new national high speed rail network,” Secretary of State for Transport Justine Greening said in a statement.