The former Birmingham City Council leader who launched the £750 million revamp of New Street Station has blasted Network Rail for ‘ruining’ his dreams.

Lord Mike Whitby, who successfully campaigned for government funding to deliver the New Street Gateway scheme six years ago, has lashed out at changes to the scheme.

The peer said that changes would make the futuristic design look ‘obsolete’ and questioned Network Rail’s motives.

Last week the Birmingham Post revealed that a revised look, submitted to the city council for planning permission, would extend the prominent white Navigation Street footbridge and leave it exposed.

Initially the bridge was to be covered by the curved stainless steel cladding which envelopes the rest of the station.

Lord Whitby said that from the outset, when he chaired the New Street Gateway delivery group he was forced to repeatedly resist calls from government to reduce the cost of the scheme.

He said: “I did not accept that we should have second best. I fought vociferously that we had waited since 1966 for a decent New Street station. The people of Birmingham wanted a world class station that would make us proud.

“I am now saddened to see this design that will clearly has a very substantial impact on that vision.”

He questioned the motives of Network Rail which last week denied that cost was a factor. A spokeswoman said that to carry out the original scheme would require either train services to be stopped for a time, or delay the reopening – which is scheduled for spring 2015 – by several months.

New picture: £600 million New Street Station as seen from top of the Rotunda

Lord Whitby said he could not believe that the design would be heavily compromised for ‘the sake of a two or three month delay’.

“This is what they argue this is about, not cost. But I believe the people of Birmingham would say ‘we have waited long enough, let’s ensure we get the design we wanted in the first place, not something which clearly looks obsolete in appearance and will ruin a fantastic design’.”

Architect and chief executive of Millennium Point Philip Singleton has previously said: “This follows the rather unfortunate debacle of the original architect not completing the atrium. Is it about making savings and dumbing down the essence of a great idea?”

This is the second time this year that Network Rail has been accused of cutting back on design at New Street. The Post revealed that globally respected architect Alejandro Zaero-Polo had walked away from the New Street Gateway project over changes to the original design for the station’s atrium using different materials.

In an interview with the Post, Mr Zaero-Polo accused project managers of “making design decisions unilaterally and without proper analysis.”

He said the change of materials would make educated people ‘cringe’. “It is up to Network Rail and Birmingham City Council to decide the kind of public they want to cater for.

“It is a mistake to allow the project managers to make design decisions unilaterally and without a proper analysis. They will obviously go for the easier and the faster, but the project will never become cheaper once the budget has been agreed.”

Network Rail has asked for permission to retain the footbridge saying that extensive works could delay the completion of the station by months or lead to the closure of the track for a period.

It has previously prided itself on the fact the station has remained operational throughout the redevelopment work, which began in 2010.

An application has been submitted to the city council’s planning department and is open for public comment until May 22. It will be decided in the summer.

Network Rail has stated that the installation of extensive stainless steel cladding over an operational railway is “impractical” – given that work could only take place for a few hours at night.

A spokesman for Network Rail said: “Birmingham City Council’s planning committee is looking at amended designs for the Navigation Street footbridge.

“The footbridge proposal was added to the planning application in 2009 and it is this design which has been altered to avoid adding years onto the construction programme. The existing structure would need significant strengthening to support the extra weight the cladding would place on it, which would require extended railway closures causing delays and disruption to passengers.

“A detailed clean of the existing structure will take place during the project and a plan will be put in place so the bridge is well maintained in the future. The redevelopment of Birmingham New Street will transform the station and help it meet the increasing demands placed on it by millions of passengers who use it every year.”