Portugal is considering charging motorists who want to drive into the centres of its major cities.Plans are being drawn up for the installation of electronic toll systems, to encourage people to make more use of public transport. The cities of Lisbon and Porto are likely to be top of the list for the new project. Finance minister Alvaro Barretto says Portugal’s reliance on petrol imports is costing the country too much. He says the aim is to increase public transport use by 15-20 percent over the next five years. The success of toll charging in the centre of London is being held up as an example, although there it was introduced more because of traffic jams and pollution. Critics of the Portuguese plan say public transport needs to be improved before people are forced to leave their cars at home, and alternative energy sources must be considered.