The transport department said public concern about the changes meant they must not take place until the new year, after a new rail franchise is awarded.

The name of the new operator who will run services in Kent and parts of East Sussex will be announced by Christmas.

Set said it was holding talks with the RMT union to try to halt the walk-out.

The Rail Maritime and Transport Union claims 100 jobs could be lost if booking office staff are replaced with machines and opening hours cut.

"If they close rural ticket offices some of the stations will have no staff whatsoever" - Kenneth Leadbeater, Dartford Borough Council

Set has insisted there will be no job cuts and staff will be redeployed as customer advisers on platforms and ticket collectors on trains.

Dartford Borough Council has campaigned against the changes and its leader Kenneth Leadbeater said he was pleased at the government's "partial reprieve".

But he added: "The campaign continues because we must ensure that the current station opening hours remain when the new franchise takes over.

"If they close rural ticket offices some of the stations will have no staff whatsoever."

Leader of the RMT, Bob Crowe, said passengers wanted staff on stations and did not want them replaced by machines.

A statement from Set said: "If the strike goes ahead next Monday we have contingency plans to make sure passengers can buy tickets - and we expect the majority of ticket offices to be open."