Transport spokeswoman Gladys Berejiklian welcomed this week's announcement the project was nearing completion but said it was two years late and massively over budget ``due to Government incompetence''.

``The project was first announced in 2003 at a cost of $106 million and was promised to be complete by 2008,'' Ms Berejiklian said.

``It has now been confirmed the cost has blown out to $344 million, which is a 225 percent increase on the original estimate.''

Transport Minister David Campbell said trains would start using the new track in April but extra services would not run until the end of the year.

Cronulla MP Malcolm Kerr said the promised additional services were less than expected.

``The express trains from Cronulla to the city are hardly express, with only four stops less than the current service,'' he said. ``It is most disappointing that this massive expenditure will see only one additional afternoon peak service.''