THE estimated cost of repair work to seven key bridges in Bolton is at least £8.5 million, the BEN can reveal.

That is the 'best guess' prediction of council engineers for essential strengthening work to seven Railtrack-owned road bridges over railways, including £2.5 million for town centre Newport Street alone.

And with six further bridges still to be assessed, the final figure could be even higher.

Bolton Council and cash-strapped Railtrack will have to thrash out between them how the bill is split.

Transport Secretary Stephen Byers could even be asked to adjudicate.

A report to councillors yesterday said: "The potential apportionment of repair and strengthening costs to the council is not yet clear."

Town hall engineers met their rail company counterparts to press for urgent action.

And in a sign of mounting frustration within the authority at the slow pace of progress, the council's legal department is considering possible steps against Railtrack if it does not show a commitment to improve the bridges.

Railtrack has told the council it is likely to be around three years before work starts because it has limited funding and its priority is rail safety.

Deputy council leader Cllr Guy Harkin said: "We were advised by Railtrack that its capital is committed for two years and even if it was to acknowledge its responsibilities now it wouldn't be until the third financial year they could act."

Cllr Peter Johnstone said: "The council believes the time proposed by Railtrack is entirely inadequate whatever their objections."

It is expected Green Lane bridge off Manchester Road, the main central route to Bolton Royal Infirmary, will be the council's priority.

The report says: "The council need to consider, and indicate to Railtrack, the relative importance of the various bridges currently affected."

Effects on traffic of the bridge closures and weight restrictions will be assessed using the council's area forum meetings.

Problems discovered are Newport Street: Minimal weight carrying capacity -- closed except to buses and taxis travelling from Great Moor Street direction. Estimated cost £2.5 million.

Green Lane: Minimal capacity -- closed. Estimated cost £0.6m.

Lostock Junction/Rumworth Road. Minimal capacity -- closed. Estimated cost £1m.

Great Moor Street: Minimal capacity -- open with regular inspectiona and lane restrictions. Estimated cost £1.72m.

Bradshawgate Tunnel: 7.5 tonnes theoretical capacity. Weight restrictions in force.

Dobb Brow Bridge: Minimal capacity -- open with regular inspections. Estimated cost £1.6m.

Bridges still being assessed are Trinity Street, Moses Gate, Soho Street, Farnworth Tunnel, Rawson Street, Orlando Street Bridge, off Manchester Road.

Bridges assessed with no problems found are Lostock Lane, Westhougthon Station Bridge, Blackhorse Street, Clammerclough Road, Blackrod Station, Mayor Street, Grimeford Lane, New Street, Ormrod Street, Dawes Street and Back Dawes Street.