SINCE the Great North Air Ambulance (GNAA) launched its first mission from Blyth, in Northumberland, eight years ago, it has rescued more than 3,500 people.

The charity was launched in 1991 by the Northumbria Ambulance Service, and immediately began the task of securing funds to enable it to operate a helicopter.

It finally secured the backing of clothing firm J Barbour and Sons, which enabled it to buy its first aircraft, a Twin Squirrel, and the AA followed with corporate sponsorship.

Since 1994, the helicopter has carried out 4,000 missions and cut response times dramatically.

The air ambulance proved most effective when responding to call-outs in remote areas, and was able to be on the scene in a matter of minutes anywhere in the North-East.

On Monday, the air ambulance charity launched a month-long trial in which a new helicopter will be based at Teesside Airport, at a cost of £70,000. Fundraisers say a second helicopter will help save thousands more lives in the region.

But concerns have been raised by the charity's neighbouring air ambulance service over its fundraising.

The Tees East and North Yorkshire Ambulance Service (Tenyas), claims GNAA is attempting to raise funds in North Yorkshire.

Tenyas has the use of the Yorkshire Air Ambulance, based at Leeds-Bradford Airport, which was launched in October 2000.

Since that time it has attended almost 2,000 incidents - and more than 550 so far this year.

And although Tenyas has repeatedly said it is happy to cooperate with GNAA in rescue missions, it is unhappy at GNAA raising funds in Yorkshire.

Tenyas has described the move as "inappropriate behaviour", and it now looks like a heated war over fundraising is intensifying.

The relationship between the two organisations sank to an all-time low yesterday after the GNAA criticised Tenyas's decision not to call out its helicopter from Teesside Airport to a crash on the A66 trans-Pennine route, on Wednesday afternoon.

Tenyas defended its decision, claiming it decides if and when to call out a helicopter to an incident in their area.

But Grahame Pickering, a former air ambulance paramedic and now chief executive of GNAA, said: "The most important thing is working together to save lives - and that doesn't seem to be happening.

"Tenyas and the Yorkshire Air Ambulance charity seem only concerned with where we can fundraise. It's ludicrous, and if it's leading to animosity then that is very, very sad."