Turning a steering wheel left when you want to turn right is confusing but the instructor smiles patiently as I bump into another pallet learning to drive a forklift truck.

Mainstream Group has welcomed clients and the media to its headquarters in the Eurolink Industrial Estate in Sittingbourne for an open day to celebrate 20 years in business.

Every year it teaches 4,500 ex-military, former prisoners and jobseekers how to drive articulated lorries, cherry pickers and other vehicles.

Its training also covers apprenticeships, warehousing, construction and streetworks, with clients including Brakes, Kimberley Clark, DS Smith and UK Mail.

It launched in a building across the road from its present site, where it has been for 12 years.

Its training director Mike Smith is the only remaining member of staff from its opening day, having co-founded the firm as a training centre for forklift drivers with his friend John Casey and John’s mother Gill.

“It was a good time,” he said. “We were very driven and totally committed to Mainstream. We were entirely focussed.

"It cost personal relationships and led to divorces. We lived and breathed Mainstream. It was a family more than a company.”

In a short time the company’s turnover grew to £14.5 million but after John and Gill’s decision to exit the firm, the trio sold their stake in a management buyout to managing director Mark Smith and a group of investors in 2015.

“It was very upsetting,” said Mike. “We had tears. John and I have gone through everything together. We thought we would retire together but we didn’t for health reasons.”

The new management team has big goals for the firm.

“They are lovely people, “ said Mike. “I have all the time in the world for them. When you get fresh blood in the business with investors you’re going to expand.”

Managing director Mark Smith had been involved in the business for 15 years as its finance director.

He said: “Mainstream has always been a successful company but it had lost a bit of its sparkle. It probably needed a bit of new direction.”

The new team quickly invested £250,000 in refurbishing the premises and training staff.

As a result, the firm has doubled its number of military contacts, which it cemented by signing the military covenant with Commanding Officer Lt Col John Hanson MBE on its anniversary open day.

The firm employs seven reservists and 46 armed forces veterans.

“They make good trainers,” said operations director Phil Linehan, a reservist himself.

“They bring leadership and trade skills. They have a lot of transferable skills and we value that.”

Mainstream is the sole provider of lorry training for newly recruited soldiers in the UK. The success has helped the company create more than 30 jobs and double the number of people it trains.

It has plans to open a similar size training centre in Ashford and turnover is approaching £20 million.

The company does a lot of work with prisons including HMP Standford Hill on Sheppey and works with 800 people a year from the jobcentre.

Mike said: “There are not many companies that can train these people. We are giving them prospects. They have made a mistake and done their sentence and want to make a go of it.

“If we give them an opportunity and they take it.”