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. \"By following in the footsteps of the 19th century railway pioneers, the government is signalling its commitment to providing 21st century infrastructure and connections -- laying the groundwork for long-term, sustainable economic growth.\" High Speed 2 will be built in two phases through to 2033, at a total cost of £32.7 billion (39.5 billion euros, $50.6 billion) at 2011 prices. Britain\'s coalition government estimates the project will generate benefits of up to £47 billion and fare revenues of up to £34 billion over a 60-year period. The network will provide high speed links between London in the south and Birmingham in central England and later to both Leeds and Manchester in the north. The government also announced plans to link London\'s Heathrow Airport to continental Europe via Britain\'s current high speed rail line HS1 which connects the capital to Paris and Brussels via the Channel Tunnel. The HS2 line from London to Birmingham and its connection to HS1 are expected to open in 2026, followed in 2032-33 by high speed links to Manchester, Leeds and Heathrow. Business leaders in Birmingham hailed the announcement, while urging the Conservative-Liberal Democrat government to avoid delaying the start of the construction work. \"This is a fantastic day\" for Birmingham and neighbouring areas, said Jerry Blackett, chief executive of Birmingham Chamber of Commerce Group. \"The national interest must come first and business in Birmingham urges the government to press on with HS2 now so that it does not become bogged down in unnecessary parliamentary procedures,\" he added. Greening said that Tuesday\'s announcement follows \"one of the largest national consultations ever undertaken by the Department for Transport.\" She added: \"It is clear from the consultation that a national high speed rail network -- High Speed 2 -- generates strong feelings, both in favour and against the scheme.\" To appease opponents of the scheme, including some members of parliament from her own Conservative party, Greening announced extra tunnelling for sections of the 140-mile route between London and Birmingham.