The bus company responsible for two double-deckers that caught on fire this week has been accused of "shocking maintenance" by one of its drivers.

Passengers were evacuated from a 152 bus in Mitcham yesterday, November 6, after its wiring overheated and started smoking.

Bus catches fire in Mitcham - moments after school children get off

This followed a blaze on a 157 bus in Wallington, Sutton, which was engulfed in flames on Tuesday afternoon after a tyre exploded.

Bus explosion: 157 bus evacuated after fire breaks out 

Abellio, which maintains the buses on behalf of Transport for London (TfL) strongly denied the claims saying there was "no substance" in them.

No one was injured in the incidents.

The whistleblower, who works for the transport company, said: "Abellio needs to be investigated.

"The maintenance is shocking.

"Staff are too scared to go to senior management because they will just get sacked."

Both buses were dispatched from the Abellio bus depot in Beddington Cross, Croydon.

The bus driver, who has worked for Abellio for more than 10 years, said: "When you are driving and get a default on the bus, you get to the engineering depot and they say keep it on the road.

"Having two buses go up in flames in the same week is unheard of.

"Those were two buses from the same garage.

"They aren't the same type of bus, which shows it's not that there's a fault with that bus, but it's the maintenance."

A spokeswoman for Abellio denied allegations of poor maintenance at the garage.

She said: "We are taking these incidents very seriously and are working with TfL and an independent assessor to identify the root causes of the vehicle fires.

"We have stringent maintenance practices in place which are well established and in line with industry best practice."

She also said there was "no substance" to claims bus drivers' maintance concerns were ignored or that they might be fired for raising concerns.

Mike Weston, TfL's Director of Buses, said TfL is making sure an independent investigation is carried out to determine the causes of the bus fires.

He said: "The safety of our passengers is our number one priority.

"In addition to the various legal requirements we have very strict contractual obligations with bus companies to ensure all their buses are safe and maintained to the highest of standards.

"We ensure our high standards are maintained by conducting regular checks of their vehicles and we are working closely with Abellio to establish the causes of the recent vehicle fires, which will include an investigation by independent experts."

The Abellio spokeswoman said the company is checking all buses of the same models to make sure the incidents are not repeated.

She said: "The safety of our vehicles is of paramount importance and we undertake regular routine maintenance on all vehicles.

"As added safeguards, our vehicles are regularly checked by the Freight Transport Association (FTA) on behalf of TfL and by the Driver & Vehicle Standards Agency (DVSA).”

Are you concerned about the condition of buses in your area? Comment below, or email louisa.clarence@london.newsquest.co.uk.