A long-awaited extension of the metro tram system through Birmingham city centre hit fresh controversy last night after a claim council leaders were attempting to change the route.

Labour accused the Tory-Lib Dem cabinet of trying to prevent the two-way running of trams along Broad Street - effectively sounding the death knell for the project.

Kath Hartley, Labour's transportation spokeswoman, said she had evidence that the council's leadership was intent on restricting the use of Broad Street to outof-city trams only. Return services into the city from Five Ways would have to use a new route "through the side streets" parallel to Broad Street.

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Such an eventuality would require fresh approval with a new Transport and Works Act and a second public inquiry.

It could delay the extension for another eight years or even kill off the scheme, Coun Hartley ( Ladywood) claimed.

Her comments were dismissed as "scaremongering" by Len Gregory, the cabinet transportation member.

Coun Gregory (Con Billesley) denied meeting passenger transport authority officials last week along with another Conservative councillor to discuss Broad Street. However, he did not rule out possible alterations to the proposed route from Snow Hill to Five Ways.

The cabinet yesterday agreed to press ahead with the street-level extension in conjunction with the transport authority.

The Tory-Lib Dem coalition has made no secret of its scepticism about running the metro through narrow city centre streets.

Councillors have previously expressed concerns about the impact of two tram lines in Corporation street and Broad Street, where hundreds of people spill out on to the street at weekends from clubs.