Police are trialling a fleet of hydrogen-powered vehicles as part of an ambitious programme to achieve zero emissions across their vehicles by 2050.

Hydrogen and fuel cell power have come into sharper focus in the UK in recent years as a possible emissions-free alternative to traditional energy sources.

The Metropolitan Police Service is embracing clean energy technology and is continuously exploring new ways to reduce emissions via alternative fuel and energy.

Seth Finkelstein, the Met's fleet services air quality lead, said: "Alongside our existing fleet of hybrid and electric cars, we want to explore whether hydrogen power could also become part of our future.

"Tuesday, October 8 is becoming recognised around the world as Hydrogen and Fuel Cell Day and it is increasingly clear that the role of hydrogen and fuel cell power will play an important role on this journey.

"We have a range of zero and ultra-low emission vehicles (including hybrids, fully electric, and hydrogen) as part of our fleet, in fact, we now have over 500 of these in operational roles.

"We are striving to increase this amount as we move forward and are continuously engaging with vehicle manufacturers around new technologies and are open to trial all new technology that can support our operational requirements, such as hydrogen and fuel cell power."

Mr Finkelstein said it should be noted, however, that as new technology is rolled out, there are always "barriers to overcome".

"In this instance, it's the availability of hydrogen refuelling stations that will need to be addressed to help further the use of these vehicles," he added.

Met Police has brought in 21 hydrogen-powered Toyota Mirais which have so far clocked up more than 260,000 emission-free miles.

Ten of these cars have been partly funded by the European Commission as part of the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) research programme through the Zero Emission Fleet vehicles For European Roll-out (ZEFER) project.

The scheme aims to demonstrate the business case for organisations converting their fleets to fuel cell electric vehicles, and thus improving the business case for hydrogen refuelling stations.