An ambitious bid to make Oxford the first place in the UK to introduce a city-wide 20mph speed limit was last night welcomed by campaigners.

Highways chiefs are considering giving every residential street a 20mph limit - including the main routes into the city.

Campaigners have had some success already, with 20mph limits introduced on some residential streets, and parts of Cowley and Banbury roads.

Now Oxfordshire County Council is moving towards covering the whole city in what has been described as a "big bang" approach.

Ian Hudspeth, cabinet member for transport, said: "We will have to look at some roads and decide whether it is really practical for people to go at 20mph all the time.

"Then we will have to decide whether to implement it zone-by-zone or go for a big bang approach, which I would favour.

"It would be easier for everyone to understand, with everything changing on a particular day."

A high-level transport meeting is scheduled for next month.

If experts decided to press ahead with the scheme, the zones could be in place by end of the year.

The introduction of a 20mph limit in Cowley Road led to a 35 per cent reduction in accidents.

Paul Cullen, of the Life Begins at 20 group, said: "I think it is important that 20mph limits are introduced on bus routes.

"These are roads that see maximum pedestrian and cycling activity, as well as being the main school routes. As well as reducing accidents, it would bring social benefits, with parents happier to allow children to go to shops and elderly people feeling safer going out."

County road safety manager John Disley said: "There is now a need for us to look at the whole question of enforcement."

Ted Dewan, of the Beech Croft Residents' Association, said: "Life Begins at 20 was launched in Beech Croft Road two years ago and we're very pleased the county council included this street in their Summertown 20mph scheme.

"I think it's terrific that city-wide 20mph limits are no longer considered a pipe dream."

County Hall puts the implementation costs at £300,000.

This week Oxford City Council called on County Hall to get on with introducing a city-wide 20mph speed limit.

Colin Cook, the city council's executive member for development, said it hoped to see all roads within the city limits included in the plans.

He added: "Residential roads are our priority. Everything else would be a bonus."