Parks are supposed to be urban oases. But in Manchester, less so.

For decades what ought to be one of Europe's most impressive public squares has been choked with buses, and fumes, and the noise of idling diesel engines. But now it looks like the unlovely public transport hub of Piccadilly bus station could be on the way out.

Concerns about air quality are at the root of the plan, the Manchester Evening News reports, adding that removing the bus station had been a long-term ambition for the city council in any case. Stagecoach bosses say they believe smog concerns are the latest smokescreen for plans to close the facility.

Stagecoach Manchester has twice been approached about either closing Piccadilly bus station entirely, or halving its size, the Manchester Evening News reports.

Manchester City Council leader Sir Richard Leese has confirmed that proposals are under consideration, although Transport for Greater Manchester says it has no immediate plans for action.

The huge volume of bus traffic through Piccadilly Gardens is in contrast with similar central piazzas in other cities: London long ago banished buses from Trafalgar Square, which was once a major terminus.

Local council leaders will consider introducing a new Clean Air Zone plan in January in an effort to cut out the smog and dangerous fumes.