Government ministers are pushing for a new criminal offence of sex advertising in phone boxes to be more stringent and wider-ranging.

Ministers want to create a specific crime of advertising prostitutes and sexual services, with fines of up to £1,000.

Originally supporters had pushed for an offence of unauthorised advertising in phone boxes, but they are now concerned this could inadvertently apply to businesses such as taxi firms.

And ministers announced yesterday they wanted the clampdown on the plague of the sex cards to be made nationwide, instead of just in particular areas such as Brighton and Hove.

MPs such as Ivor Caplin had warned ministers a localised law would only shift the problem from one area to another.

Mr Caplin said: "I'm pleased the Government has accepted the suggestion put forward by myself and colleagues in order to create an offence of sexual advertising in phone boxes.

"This unnecessary intrusion in phone boxes is closer to coming to an end than it has been for many years."

Home Office Minister Lord Bassam of Brighton said phone boxes would not be the only places where people could be prosecuted for advertising the service of prostitutes.

He told the House of Lords: "There should be a power to extend the offence to other structures providing shelters for the public such as bus shelters."

Lord Bassam said the Director-General of OFTEL was consulting with the telecommunications industry about how to bring in call barring systems.

He said this and the new criminal offence would enable the authorities to crack down on carding.

He said: "This will protect local communities from the obvious nuisance that these cards cause."

Home Office Minister Paul Boateng believes the cards are an "offensive nuisance" and says they create a bad impression with foreign visitors and are a bad influence on young people.

The Government published a consultation document on the proposed changes in May last year.

But legislation outlawing sex cards is unlikely before the next General Election - likely to be in less than six months.