Buses delivered to the island up to a month ago are still sitting in the depot unused.

The Department of Infrastructure buys new buses every year to replace older ones in preference to maintaining them. It says this cuts back on running costs.

This year, the DoI, through Bus Vannin, has bought 10 double decker buses, the first of which was delivered on August 10, with the most recent arriving on September 9.

However, rather than being pressed into service, iomtoday has learned the buses have not yet been used and they remain parked up at the depot at Banks Circus.

A spokesman for the DoI explained this is because the buses ’are awaiting pre-delivery inspection and fitting of equipment, plus driver training’.

He added: ’These buses have been delivered using a different system to our normal Citaro deliveries. The Mercedes buses are delivered with registration plates - in England, Scotland and Wales vehicles are registered by the dealer.

’These were built in Northern Ireland and therefore are registered by us upon arrival. Some registration plates are now fitted.’

The DoI also confirmed that since purchasing the new buses, it has sold five buses to a UK operator, which it did not name.

It said that these buses left the island in August. They had been purchased in 2009 and are 11-and-a-half years old.

At the end of last month, Bus Vannin received delivery of its first hybrid buses. Like the rest of the fleet, these were supplied by Mercedes.

Six Mercedes Citaro single-deck low-emission hybrid vehicles were acquired which combine a conventional internal combustion engine with an electric propulsion system.

Public transport bosses say the aim is to increase sustainable forms of public transport.

But they have no plans to introduce all-electric buses, insisting there are no zero-emission vehicles currently available that have the power and range required.

Since the introduction of the hybrid buses, Bus Vannin has earmarked six traditional Citaros to sell, but it has not yet sold them.

These buses date from 2011 and are for sale for £40,000 each at www.coachandbusmarket.com. Each bus has done just over 400,000 miles.

A Freedom of Information request in July 2018 revealed that Bus Vannin had a fleet of 52 Mercedes buses comprising 33 Citaro single deckers, which cost between £134,490 and £169,100 each.