Government plans to re-privatise a rail franchise have sparked fury from unions which wanted to keep it publicly-run.
Dover feared the Shakespeare Tunnel would rule it out of the CTRL
Four groups have been asked to bid for the new franchise to take over from South Eastern Trains, currently run by the Strategic Rail Authority.
The franchise will include routes in Kent, south-east London and East Sussex into London and high-speed services on the Channel Tunnel Rail Link.
"Re-privatisation should be shelved," said RMT union leader Bob Crow.
Punctuality has improved since the SRA took over running South Eastern Trains in November 2003 when the government terminated Connex South Eastern's franchise.
"The Government has said it will stick with what works and they now have the chance to prove it by leaving South Eastern Trains in the public sector," said Mr Crow.
"If it isn't broke, why on earth try to fix it?"
Gerry Doherty, general secretary of the Transport Salaried Staffs Association, said: "There are no discernible benefits to the passenger or taxpayer in re-privatising the service."
Danish Railways, French transport firm Kolas and Hong Kong company MTR are among those involved in the bids.
A decision is expected in the autumn.
The franchise-holder will run the new 140 mph services into St Pancras on the Channel Tunnel Rail Link.
The SRA announced on Monday the list of stations to be served.
'Good news for Dover'
They include Ebbsfleet, the Medway towns, Ashford, Canterbury, Ramsgate and east Kent, including, provisionally, Dover Priory.
Dover feared it would be left out because of problems with the Shakespeare tunnel and its inclusion was welcomed by Dover and Deal MP Gwyn Prosser.
"This is good news for east Kent and Dover," he said.
"We can look forward to seeing Dover, the busiest ferry port in the world, linked up to London."
Transport secretary Alistair Darling said there would be 10% more services into London.
"Journeys from Ashford to central London will be reduced by 40 minutes each way."
SRA managing director for operations Nicola Shaw said: "The new franchise...will provide improvements to journey times, along with better punctuality.
"We look forward to the competitive bid process."