Drivers are still travelling an average of 25mph over the speed limit on the Sheppey Crossing - despite tighter restrictions.

And the introduction of the temporary 50mph limit has seen average speeds drop by just 5mph.

The revelations come following several serious crashes on the bridge, including the death of a mother and son Deborah and Marshall Roberts in July last year.

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And the bridge was also the scene of the UK's largest ever pile-up, involving more than 150 vehicles in September 2013.

At a meeting with Highways England, Sittingbourne and Sheppey MP Gordon Henderson discussed the bridge with Highways England, and said the new speed restriction appears to have had a limited impact.

The average speed for island-bound traffic before the change was a staggering 80.55mph.

It has since dropped to 75.38mph, while in the opposite direction it has fallen from 78.15mph to 72.71mph.

Kent Police has responded by planning an operation to enforce the 50mph limit, but it is not yet clear what this will involve.

Mr Henderson said: “Highways England have assured me that their ‘expectation’ is that “nothing is off the table” and their reports must simply identify what, where and how the bridge can be made safer.

“It will then be for Highways England and the government to decide the exact work that will be undertaken.

“At that stage I can assure you that I will lobbying very hard for the right measures to be taken, whatever the cost implications.”

The current 50mph limit will stay in force for 18 months, during which longer-term plans will be made regarding the permanent speed and how it can be enforced.

Kent Police, which wrote a report recommending the lower limit, is continuing to press for a permanent change.

Highways England recently met with the company responsible for maintaining the A249 to discuss a range of possible measures, including painting chevrons on the road, according to Mr Henderson.

The firm is gathering data, and concerns raised during the design and build phase of the bridge by now retired traffic liaison police officer, Richard Denyer, will be part of this examination.