Rail bosses have promised a passengers' watchdog group major improvements to their services if they win the new South Central franchise.
Current operators Connex, and rivals Govia, were each given five minutes to say why they deserved to win the right to run services in Sussex for the next 20 years.
The showdown took place when the Rail Passengers Committee for Southern England met for the first time in Chichester.
Olivier Brousse, deputy managing director of Connex, and Keith Ludeman, from Govia, were questioned by committee members, but the watchdog group is not formally backing either bid.
West Sussex County Council told the committee it was remaining neutral but wanted the winning company to tackle basic issues first such as clean and reliable trains.
The council also wants action to improve stations on the Coastway line saying some are so "unpleasant" they give visitors a false impression of the towns along the route.
Mr Brousse said Connex would invest £1.5 billion into services with all slam- door trains being replaced by 2002.
He said 900 new carriages would be air-conditioned with better facilities for the disabled and CCTV to make passengers feel safe.
In Sussex, he said, Connex would reopen the Uckfield to Lewes line and improve the Arun Valley line into London.
He added: "There will be station refurbishments and I don't mean a lick of paint which it has been in the past."
Mr Ludeman said Govia's main aim was to run a safe railway system.
The company's bid was based on "drivers, drivers and drivers" because it was impossible to run reliable and punctual services without a full driving staff.
Govia says it will invest £800 million on new trains and improve the speed of services on the Coastway line.
Mr Ludeman said of the bid: "It is not a book of promises, but a package which we can deliver."
Deputy Prime Minister John Prescott is due to make a decision soon on the latest round of rail franchises.
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