Britain's first 'air taxis' could be picking up passengers within four years, a technology company has claimed.

Vertical Aerospace, a Bristol-based start-up founded in 2016, has built and flown the UK's first electric vertical take-off and landing aircraft, a significant milestone for the transport industry's flying taxi ambitions.

The firm said it had ambitions to make personal air travel on-demand and carbon-free.

Equipped with four propellers at the front and back of a helicopter-shaped body, the vehicle's vertical take-off and landing technology would allow it to travel between exact locations, without a pilot having to make diversions to an airport.

The company obtained permission from the Civil Aviation Authority to operate the aircraft and in June flew a test flight in Kemble, Gloucestershire.

It is currently capable of a five minute flight time at a top speed of 80kmph. The company has since flown a dozen test flights.

The start-up said it one day plans to add autonomous flights and an on-demand service, meaning users could call a flying taxi to their location. The start-up said it plans to launch an intercity air taxi service by 2022.

A number of different companies have shown interest in flying taxi services. Uber, the ride-hailing app, plans to launch a pilot scheme for electric flying taxis in Dallas and Los Angeles in 2020 through its uberAIR venture, while British firm Rolls-Royce announced in July that it has built a propulsion system for a flying taxi. Lilium, a German start-up, made the world's first electric vertical take-off and landing aircraft in 2017.

Stephen Fitzpatrick, founder of Vertical Aerospace and chief executive of OVO Energy, an energy supply company, launched his project after a stint with British Formula One company Manor Racing.

Mr Fitzpatrick said current short journeys by air were inefficient, with journeys to and from the airport taking longer than the inter-city flights themselves.

"Passenger numbers for short-haul flights have exploded in recent years," he said, "but as a result aviation is now a major contributor to climate change local air pollution. Congestion around airports has become a huge problem for flights of 500 miles or less."

OVO's focus on renewable energy led Mr Fitzpatrick to make the flying vehicle electric as a means of reducing the carbon footprint of air travel, currently accounts for around 3pc of all Europe's greenhouse gas emissions.

Vertical Aerospace sees a big opportunity for the UK to take a lead in the flying taxi industry given its heritage in aviation.

It aims to launch taxi services on specific intercity routes in the next four years, such as journeys from Bristol to London or Sheffield to Liverpool. But sector faces significant regulatory hurdles. In the US, the Federal Aviation Administration has met Uber's flying taxi plans with caution.

Mr Fitzpatrick said Vertical Aerospace was working with the European Aviation Safety Agency to gain certification for its next model.