The West of England's Labour Metro Mayor Dan Norris has backed a crackdown on "rip-off" petrol prices by supermarkets overcharging hard-pressed residents for fuel.

It comes as the top four petrol supermarkets were named and shamed in a report by the UK's fuel watchdog for overcharging drivers by around £900 million last year.

Supermarkets made an extra 6p profit on every litre of fuel they sold in 2022 by keeping prices high, according to the damning report by the Competition and Markets Authority.

Asda and Morrisons in particular "significantly increased" margins at the expense of struggling customers during a cost-of-living crisis, according to regulators.

Mayor Norris has backed new rules to introduce a 'petrol price finder' website to show drivers online where they can bag the best deals, with the expectation this will see firms forced to pass on falls in wholesale prices over the coming weeks to consumers.

But he wants ministers to go further by coming forward with more measures to clamp down on oil companies as well as supermarkets profiteering during the cost-of-living crisis, and to protect consumers, saying the whole oil market needs "rebalancing".

The AA said it had been calling for this type of price tracking since at least 2012, when it first investigated similar schemes in Austria and Denmark.

Mayor Dan Norris said: "This probe has confirmed what many of us have long suspected - that supermarkets have been hiking petrol prices even though the wholesale cost was coming down. To the detriment of hard-pressed residents. A petrol price finder, as the regulator is proposing, is important but must be just the start. The whole system needs a shake up, and it needs it now.

"Because from oil and tax giants rolling in extra cash because of Putin's illegal war in Ukraine, to greedy supermarkets hiking prices during a cost-of-living crisis and then denying it, the big business world of oil companies and huge supermarkets profiteering at everyone else's expense needs rebalancing. And that requires a firm grip by government, so that consumers, not shareholders become the priority. The market isn't working, and the Conservatives are too entangled to be able to put the public first at a time where thousands in my region face a cost-of-living squeeze."