Motorists must pay to use the Dartford crossing

Andrew MacKinlay, MP for Thurrock in Essex, said drivers could pay �1.50 to cross from north of the border.

He is angry that his constituents are bearing the brunt of experimental pricing schemes to use the Dartford crossing between Essex and Kent.

Northumberland and Cumbria county councils both dismissed the idea of a toll scheme as unrealistic.

Bill Brooks, leader of Northumberland County Council, said he initially thought the comments were a joke.

He said: "When I first heard this, I had to check my calendar to see if I was being led on a by an April fool.

"This is clearly an MP from the South East who has no understanding of the issues in Northumberland.

'Tongue-in-cheek'

"We don't have the public transport benefits, the infrastructure, that they have in Essex - there's a heavy reliance on cars.

"The A1 needs to be dualled but the answer is not to ask the Scots to pay for it."

Mr Brooks' views were echoed by MSP Fergus Ewing, transport spokesman for the Scottish National Party, who thought the comments were a tongue-in-cheek attempt to draw attention to transport issues in Essex.

He said: "It does raise some interesting possibilities.

"Do they want to use the money to rebuild Hadrian's Wall perhaps?"

A spokesman for Cumbria County Council said a Borders toll scheme did not sound like a realistic idea.