Government approval for the refurbishment of New Street Station brings to an end a campaign unique in Birmingham and the West Midlands. In a rare display of determination, politicians across the party divide, MPs, public bodies and representatives from the business sector and trade unions joined together to make the case for a transportation project of local, regional and national significance.

Historic differences were set aside and it was agreed that New Street would be the region's number one transport policy. It would be at the top of the agenda every time an opportunity arose to bend a Minister's ear, every time a council delegation found itself in Whitehall and every time business leaders were asked by the Government for their views on policy-making.

In short, the New Street drum would be well and truly banged for as long as it took to get a result. It was a blunt, outspoken campaign, hardly sophisticated, but not the sort of thing that the West Midlands had been very successful at in the past. And after four years of intense action, it worked.

It would be wrong today to do anything other than praise the efforts of the Gateway Plus partnership. The new New Street will transform the passenger experience, doubling the number of customers able to use the station in comfort. For the first time, Birmingham will have something that looks like an important railway terminal and entrance to the city seen by a staggering 52 million passengers a year, rather than a dank hole more akin to a sewer.

But what's being planned is far more than a simple station, since Gateway Plus will also open up significant regeneration opportunities in a run-down part of the city centre. It was heartening to hear from Ruth Kelly, the Transport Secretary, that the potential for regeneration and improving pedestrian connectivity finally persuaded the Government to back the project with hard cash - supported by the single largest contribution by a regional development agency anywhere in the country.

There are, however, limits to what Gateway Plus can deliver. Some critics have likened what is being proposed to the construction of a new shopping centre on top of the same old, drab, station. That is unfair. The finished product will have longer and better platforms, plenty of lifts and escalators as well as sweeping glass-covered passenger concourses more reminiscent of airports than railway stations. The design, we are promised, will have the "wow factor" in abundance.

But there is one inconvenient truth about all of this. Birmingham's new station may match the revamped Savoy Hotel for luxury, for all we know, but the interminable bottleneck queues of trains waiting to enter New Street will continue until the four-tracking of the West Coast Main Line between Coventry and Wolverhampton is approved.

There was no sign from Ruth Kelly yesterday that additional track is planned any time soon. Indeed, Ms Kelly appeared blissfully unaware of the importance of four-tracking, repeating only the mantra that Gateway Plus will double capacity. It certainly will, in terms of the number of passengers able to wait for trains. It will do nothing, however, to allow significantly more trains to access the station quickly.

Clearly, the case for four-tracking still has to be made at the highest level, alongside campaigns to secure the rest of the infrastructure needed to make transportation in Birmingham and the West Midlands world class. Three of the Gateway partners - Birmingham City Council, Centro and Advantage West Midlands - are already beginning to make encouraging sounds about capturing the team spirit displayed in the New Street bid and diverting it towards the runway extension at Birmingham International Airport and the new Metro routes planned for Birmingham city centre and the Black Country.

It is vital to seize the moment. There is an opportunity now to exploit the success of New Street - pointing out to all of the region's councils, public bodies and business organisations that effective campaigns do produce results - and focus all our energies on the airport and the Metro. The potential rewards are immense; failure is not an option.