Small businesses will be driven out of the borough if Ken Livingstone's plans to charge pollution-producing lorries, buses and coaches that enter London gets the go-ahead, Barnet Council warned this week.

The council has told Transport for London (TfL) that it is particularly concerned' about the effects the multi-million-pound Low Emission Zone (LEZ) will have on borough-based small businesses and coach companies running services for schools.

Criticisms regarding the financial impact on the council and the feasibility of the proposals have also been levelled at TfL. The council believes that plans to install only 45 enforcement cameras across London will not be enough to prevent non-compliant lorries entering the zone.

"If this is the level of enforcement planned by TfL, it will not be sufficient to deter drivers of polluting vehicles," said a council spokeswoman.

"Furthermore, as the fixed cameras will be placed on main roads, drivers of polluting vehicles may use quieter, residential roads to avoid detection." The authority's position was set out in a letter to TfL last month, sent as part of the consultation process for the environmental scheme.

The LEZ aims to encourage drivers to reduce emissions by either replacing or modifying older diesel engines. Those who do not comply will have to pay a substantial daily charge to drive within the M25, although an exact price has yet to be determined. The scheme could be in place as early as 2008 and may be extended to include vans in 2010.

The council spokeswoman added: "Goods vehicle operators based outside London will be able to adjust the use of their fleet to ensure only compliant vehicles are used within London. Operators based solely within London will not be able to do this and will either have to replace their vehicles or pay the charge. This may result in companies moving to sites outside London to avoid such costs.

"Coaches used for school transport tend to be older vehicles and are less likely to comply with the emissions threshold. The council is concerned that coach operators may find it uneconomic to continue providing school services and this could result in an increase in congestion and pollution associated with the school run if services are withdrawn."

The Mayor of London and Peter Hendy, head of TfL, have consistently backed the implementation of the LEZ.

Mr Hendy told the London Assembly in March: "We are in the process of implementing the Mayor's proposed Low Emission Zone (LEZ), which will make a further contribution to air quality not only within central London but through the whole of Greater London. "