A petition against the introduction of a system of road charging has been heralded “a huge embarrassment for MPs” by Government critics.

Hosted on the Prime Minister’s Number 10 Downing Street website, the number of signatories could reach 1.7 million before it closes on 20 February.

In a BBC interview, cabinet minister, Ruth Kelly said politicians have a “duty to listen” to the strength of public opinion.

The Prime Minister responded this week by directly emailing the signatories to further continue public debate on the issue.

Such was the popularity of the debate, there were reports that the PM’s website was brought down at least once by sheer weight of traffic.