Motorists have reacted with fury after the Dart Charge was increased for account holders by 20%, 15 years after it was meant to have become free.

Currently car owners using the Dartford Crossing who have a pre-paid account pay £1.67 per crossing, a third lower than the £2.50 paid by those without an account.

But yesterday they received an email informing them from October 1 they will be charged £2, 20% lower than the standard rate.

It read: "As an account holder you will continue to benefit from a discount to the standard rate".

All other rates will remain the same.

Highways England spokesman Valerie Amar-Matthews said: "More than a million people are eligible to save money on every crossing at Dartford after having signed up to the Dart Charge pre-pay account.

“With more than 55 million vehicles travelling over the Dartford Crossing every year, there is an ongoing need to manage increasing demand at the crossing.

"After nine years of operating a 33% discount for cars, the Department for Transport has reviewed how fairly the benefits to account holders are spread across different vehicle types and have aligned the Class B rate more closely to Classes C and D."

The link between Kent and Essex was opened in 1963, in 1999 following a number of hikes in the toll the government said it would become free once it had paid for itself, which was supposed to be in 2003.

But they backed out of that agreement and last year we reported how more than £53 million had been paid in fines since barriers were removed in 2014.

If no payment of the toll is made online by midnight the day after your crossing a fine of £70 is imposed, which is halved if paid within 14 days or increased to £108 if not paid within 28 days.