High speed trains in Kent have helped transform the economy of the county and brought in millions of pounds in investment and jobs, a conference was told today.

The event marked the 10th anniversary of the service and the first decade since the Hitachi maintenance depot in Ashford opened.

Industry experts and others heard an optimistic and upbeat assessment of the impact of HS1.

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But there was a warning that it might become a victim of its success with forecasts that passenger numbers were expected to grow by a staggering 140% by 2044.

The conference was told by rail chiefs how HS1 had directly boosted growth and investment in Ashford and many other parts of the county.

Southeastern managing director David Statham said the service was the company’s “jewel in the crown”.

“The growth in passengers has been phenomenal - when we started we carried 7m passengers. That is now 15.3m. Towns like Margate, Folkestone and the Medway towns are seeing growth that in part because of the way the service has improved connectivity.”

He said HS1 had not just benefited commuters but had helped draw visitors to the county, boosting tourism.

Leisure journeys to Kent via the high speed route have increased nine-fold since 2010, up from 100,000 to 890,000 per year.

Asked whether there was any likelihood of the premium fare being reduced, he said that was a matter for the Department for Transport but said the costs of building the infrastructure needed were still being repaid.

“There was a massive amount of infrastructure to set up HS1 and there some costs to be recovered," he added.

Ashford MP Damian Green was among the speakers at the conference but sidestepped journalists who were waiting to try to speak to him about the government’s troubles and the claim by Charlie Elphicke that the Dover MP had not yet been told why he had been suspended from the party.

Earlier, he told the conference: “In terms of prosperity, HS1 has been the biggest and best thing that has happened in Ashford for 100 years.”

Developments in the town were directly linked to the service, he added.

“It is a reasonable question to ask whether any of this would have happened without it. I very much doubt it.”

While he did get complaints every year when annual season ticket prices were announced, most commuters “did not mind so long as the service was reliable and fast”.

Transport Focus chief executive Anthony Smith said the service had almost become too successful.

“It is the Achiles heel... you have been too successful; we need more trains and longer trains. That will be the key to the next franchise,” he said.

The conference heard how the Hitachi depot in Ashford, where the fleet of Javelin trains were maintained had also played a critical in helping the town grow and had a 129-strong workforce.

To mark the 10th anniversary, a specially commissioned statue of a red-topped crane, a bird that symbolises good luck and longevity in Japan, was unveiled at the depot to welcome visitors.