Following the global slowdown and economic crisis, Queen Elizabeth II is determined to switch from the LPG-fuelled black cab to an environmentally friendly car service to save money.
The queen's staff at Buckingham Palace has signed up with Toyota's 'Green Tomato Cars' to cut costs, after they found out about the car from Prince Charles's London office, which switched to its cheaper carbon-efficient Toyota Prius fleet, the Daily Express reports.
"They were very conscious of the savings they'd be making both in financial and carbon terms. Cost was certainly a major factor, so much so in fact that Clarence House negotiated a discount," said Tom Pakenham, director, Toyota.
"Prince Charles was one of our first customers and his staff have been using us since we launched in 2006. Now, we are the first choice for both Clarence House and Buckingham Palace," he added.
According to the company, Green Tomato Cars' petrol and electric hybrids average about 56 miles to the gallon compared to 36mpg for a black cab, making them the cheaper of the lot for more than 75 per cent of journeys.
"We have raised the subject of the royals themselves using our cars, not just their staff, but security and speed are problems we would need to overcome first," Pakenham said.
Following reports of the queen running out of funds by 2012, the switch to eco-cars is among many decisions taken by the queen to cut costs.