Birmingham New Street is already one of the UK's most congested, taking some 120,000 passengers per day in a station designed to take half that number. This number is set to increase by a further 30% in the next 10 years.
The station also has the lowest customer satisfaction rating of any Network Rail-managed station, and its renovation will have few detractors.
Transport Secretary Ruth Kelly, said the Government will provide the funding grants sought by Birmingham City Council, Advantage West Midlands and Network Rail to transform the station.
The scheme will double the size of the station concourse. 31 escalators will feed onto platforms, replacing the five existing escalators. Three new entrances to the station could open the area to the south of the station to further development, currently blocked by the station itself.
"Birmingham is a key gateway to towns and cities across Britain and this investment will make New Street a more enjoyable experience for the 17M passengers who use it each year," said Kelly.
"This scheme has been in development for some time and has improved immeasurably so that it can now meet the needs of passengers and deliver a much needed boost to capacity. The Government is making a major investment in Birmingham New Street and it is now up to Birmingham City Council and its partners to transform this station into one of the best in our country."
John Hutton Secretary of State for Business, Enterprise & Regulatory Reform said: "This development will both improve facilities for businesses in New Street and create an extra 5000 jobs in the area. This is why AWM has made their largest ever funding award to this exciting project, which will propel Birmingham and the more than 350,000 businesses of the West Midlands to greater prosperity."
Liam Byrne, Minister for the West Midlands, said: "This is simply fantastic news for Birmingham and the West Midlands. I want to thank Ruth Kelly and John Hutton for their huge vote of confidence today, and to Birmingham and its partners who worked so hard to sweat the details since last summer. But the real credit goes to the people of Birmingham and the West Midlands who gave such voice to the campaign for New Street.
"Today the region gets its reward. I said a new New Street was my number one priority as Regional Minister. Today is proof that the West Midlands can get huge deals done when we set ambitious goals and pull together as a team."
Network Rail and Birmingham City Council plan to start work in 2009, with the project completing in 2013/14.