Ealing Friends of the Earth (EFoE) is lobbying the government for tighter pollution laws after monitoring stationary buses pumping out poisonous gases for up to 17 minutes.

EFoE wants bus companies fined after setting the stopwatch on buses standing with running engines at Haven Green by Ealing Broadway station and Ealing Hospital on Saturday last week.

The worst offender was a driver on Route 297, who left the bus engine running for 17 minutes ,, a record in EFoE's three years of monitoring.

The second worst offender was Route 65 at Haven Green, which pumped out fumes for 14 minutes ,, double the longest time recorded last year ,, followed by Route 112 which left the engine running for 12 minutes ,, six times longer than last year.

'This is becoming a joke,' said Christine Eborall, health and pollution spokeswoman for EFoE. 'After last year's dismal results, London Transport and the bus companies came up with the usual platitudes about drivers being trained to switch off engines.

'But our results prove that relying on driver training is just not working.' In 1998 the government released a report that estimated the inhaling of small particles from diesel emissions contributed to around 10,500 hospital admissions for respiratory disease in Britain.

Ms Eborall is now writing to the borough's three MPs and its GLA representative Richard Barnes asking for power to be given to local authorities to fine offending vehicles. She is also pressing Ealing Council for action. A spokesman for Ealing Council said it had no power to deal with the pollution problem in Haven Green and outside Ealing Hospital but was waiting for the government to declare Air Quality Management Areas (AQMA)in the borough. 'Once AQMAs are established, the council will produce an action plan to deal with the problem.'

A London Transport spokeswoman said individual bus companies were instructed not to leave their engines running. 'We realise that running engines significantly affects air quality, even though we're working rapidly to reduce the harmful level of exhaust emissions, and we will be contacting the bus companies concerned.'

Sean O'Shea, operations planning manager for Metroline, the worst offender, said the company would be monitoring the situation in Haven Green and Ealing Hospital.