Beleaguered broadband users in Norfolk were finally promised a better service last night as it was revealed that BT has started a major upgrade of telephone exchanges - but some customers will have to wait up to three years before they reap the benefits.

Beleaguered broadband users in Norfolk were finally promised a better service last night as it was revealed that BT has started a major upgrade of telephone exchanges - but some customers will have to wait up to three years before they reap the benefits.

It emerged that BT has started work to increase broadband speed up to a maximum of 24 megabits per second by 2012, while help is also being planned for those in rural broadband 'not spots' with poor access or slow speeds.

In a county which has seen increasing complaints about being left behind on the information super-highway, the moves mean people will soon find it quicker and simpler to do things like log on to Facebook, tune into BBC iPlayer and watch live sport on their computers.

News of the work came to light after three Norfolk MPs met BT regional director Peter McCarthy-Ward to raise public concerns.

Mr McCarthy-Ward told the EDP last night: 'We are working on improving the capabilities of our exchanges to deliver faster speeds of 24Mbps.

'The first stage of this has already begun in Norwich. The people of Norfolk and Norwich

will soon see the benefits.

'I don't know how many exchanges will be upgraded. It will be based on customer demand.'

Mr McCarthy-Ward added that the problem of 'not spots' would be explored by investigating new wire technology and the introduction of I-plates to reduce interference.

Welcoming the move, the MPs warned last night that BT must honour its 2012 deadline to prevent the county being let down again.

Work to upgrade some of the county's 143 telephone exchanges has already started in Norwich - though BT said not all of them would be modernised to speeds of 24Mbps.

Some 'not spots' only have internet access speeds of 0.5Mbps, with towns and Norwich reaching up to 6-8Mbps.

Richard Bacon, MP for South Norfolk, said: 'I am pleased BT seems aware of the problem our constituents are facing and is keen to drive forward improvements to broadband access in Norfolk.

'The planned upgrade should deliver broadband at speeds of up to 24Mbps across the county within three years.

'Time will tell how effective these plans will be and we must keep up the pressure on BT to make sure it sees the improvements through. Norfolk cannot be allowed to fall behind.'

Chloe Smith, the new Norwich North MP who said she only had a broadband speed of 2.5Mbps at home, promised to keep a close eye on BT's modernisation plans.

She said: 'It is incredibly important to make sure this actually happens. I for one will keep on top of this.

'Businesses and households in Norfolk - urban and rural alike - need reliable and affordable broadband. Along with a better rail service, Norfolk needs this kind of basic modern infrastructure.'

The Norfolk 24Mbps rate is well above a recommendation in Lord Carter's Digital Britain report that everyone in Britain should be able to access broadband at speeds of 2Mbps - the minimum needed for people to properly download attachments, use iPlayer and enjoy the social network site Facebook.

In the last year, the EDP has highlighted problems of low-speed broadband with villagers in the likes of Tittleshall, Stowbridge, Clenchwarton and Happisburgh complaining of a poor service.

And Brian Potter, owner of Potters Leisure Resort, Hopton, near Yarmouth, claimed low speeds could prevent him holding major sporting events there.

Mr McCarthy-Ward said the problem of 'not spots' had four main causes. Most Norfolk telephone exchanges were still connected to individual copper wires which were vulnerable to electrical inference at home.

Long telephone lines, bottlenecks between local exchanges and the national network, and the quality of internet service provider facilities also affected broadband speeds.