Thefts of fuel from vehicles have doubled since the beginning of the year, with Greater London showing a 500% increase.
RAC figures show that only Wales and Scotland have seen less than a 50% rise as motorists struggle to cope with record-high prices.
Patrolman Prakesh Patel said: "These figures are clearly symptomatic of the desperation motorists are feeling amid rising fuel costs.
"Until the Government acts in the interest of motorists and reduces, and not just freezes, taxes, I fear we are at the beginning of a worrying trend."
"Victims don't just have to fork out for replacement fuel - there is also evidence that running cars with insufficient fuel can cause additional damage. Fuel pumps can become overheated or moisture can get into the tank which can make it rust.
"We are urging drivers to be more vigilant to both protect their own fuel stock and also report anyone who is trying to make money by selling on stolen petrol."
Increases by region this year: Greater London 500%; South West England 218%; West Midlands 100%; North West England 100%; East Midlands 85%; South East England 57%; Scotland 27%; Wales 25%.
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