Conservationists and residents have objected to the size and number of yellow signs put up to warn motorists about the Bath Half Marathon.

The signs attached to lampposts warning about road closures and parking bans on race day were put up six weeks ahead of the race, which takes place on March 11.

The Bath Preservation Trust says the signs are an eyesore, particularly in the elegant setting of the road used as the start and finish area, Great Pulteney Street.

But council officials say the size, number and timing of the signs has been dictated by decisions made by tribunals adjudicating on disputes over tow-aways and fines.

Trust conservation officer Joanna Robinson says the signs at Great Pulteney Street "severely detract from the character and setting of this highly significant and sensitive location".

In a letter to Bath and North East Somerset Council, she said: "The signs are visually intrusive in the long and short views of Great Pulteney Street, and contribute to clutter, which has an accumulative detrimental impact citywide.

"The trust questions whether it is it really necessary to put up large yellow signs on every lamppost warning about the road closure for the half-marathon six weeks before the day. We understand that residents and others who park there need advance warning, but surely a leaflet through the door a month or so ahead, with the signs only going up a week ahead, would be perfectly adequate."

Resident Malcolm Purvis, who lives in the Great Pulteney Street area, said the size of the signs was "ridiculous".

"In one of the most beautiful streets in Europe, in a World Heritage city like Bath, this should not be allowed."

The council says the new signs have been used successfully in the sensitive central London borough of Kensington and Chelsea, although the trust has suggested officials in the capital have now scrapped them in favour of smaller ones.

A B&NES spokesman said it had taken legal advice on the appropriate signage to use and the necessary advance notice periods when operating parking bans and tow-away schemes.

"The parking at many locations across the city is available to non-residents or residents in the whole parking zone. Therefore a leaflet drop will not adequately inform all potential drivers of the pending restrictions.

"In order for the council to be able to legally enforce a parking restriction, we must comply with the legal process. Leaflet drops are not part of the prescribed process for notifying a parking restriction.

"The council has encountered problems in the past when people have been on long holidays, away at university or in hospital, etc. As a result of these potential issues, six weeks' advance posting of the notices is necessary. This is not simply a personal view but is the timescale that the Traffic Penalty Tribunal considers a reasonable advance notice period."

Race director Andrew Taylor said he was following council instructions but that the six-week advance notice period had been normal practice for some years.

He added: "We are very grateful for the support for the event from local residents and businesses, and we work closely with the council, the police and other agencies to try to minimise the inevitable disruption caused by the event."

Details of the road closures and parking restrictions are on leaflets being delivered to properties on affected streets and on the race website www.bathhalf.co.uk.