A new railway station at Southland shopping centre is likely to have few of the amenities voters were promised at the last state election, because the Coalition grossly underestimated the project's cost and is now looking to build it as cheaply as possible.

The planned station would be built without the promised waiting room, lifts, bike cage, two-bay bus interchange and drop-off and pick-up zone, according to state government documents. It would also have no public toilets, and just 10 per cent of the platform area would have shelter, although it would have facilities for protective services officers.

Lengthy negotiations with Southland owner Westfield, which the Napthine government hopes will help pay for the station, will delay its opening until at least 2016-17, some six years after the Coalition made its promise. When it does open, it will become the fourth-busiest station on the Frankston line, attracting 4400 passengers a day, modelling by transport consultancy Sinclair Knight Merz forecasts.

Both the Coalition and Labor committed at the 2010 election to build the station, with the Coalition heavily undercutting Labor's $45 million costing, promising to build it to the same standard for just $13 million.