Edinburgh city councillors say they are prepared to carry out their threat to close down streets that fail to meet strict air-quality targets.

Princes Street, North Bridge, Haymarket and George Street all face being earmarked for a car ban in the wake of the rejection of congestion charging in the city’s referendum.

Those who took part in the poll voted three to one against the introduction of a £2-a-day charge to drive into the city.

Cities across the UK will face being hit with hefty fines by the European Union if they fail to meet nitrogen dioxide targets which become mandatory by 2010.

Senior councillors say they could be left with no alternative if a drive to improve the city’s public transport and plans to shake up city centre traffic - which include banning cars from Princes Street during the day - fail to have the desired result.