Premier Nathan Rees announced, at the NSW Labor State Conference on Saturday, that building of the $1.3billion, 11.4-kilometre stretch between the growth areas of Glenfield and Leppington would begin in the middle of next year.

Mr Corrigan told the Advertiser on Monday that he had kept trying to remind people that the Government had deferred the South West Rail Link; it never cancelled it.

``I was always confident that when conditions improved and when the time was right that it'd be announced,'' he said.

It has been a year since the Glenfield-to-Leppington project to serve new housing estates was deferred in the mini-budget.

The development expected to be completed by 2016 was announced in 2005 by former premier Bob Carr, and was supposed to be finished by 2012.

But Mr Rees said this week that the announcement was part of a ``fresh approach''.

``You will see more of my own agenda and major changes because that is what the people of NSW have demanded of me. This is a fresh approach,'' Mr Rees said.

He attributed his change of stance to the lobbying of MPs Geoff Corrigan, Graham West and Andrew McDonald and said a new station and commuter car park would be built at Leppington.

``This project will give residents in south-west Sydney access to a brand-new rail service, meaning that even more people can leave the car at home and use public transport.''

Camden Mayor Chris Patterson said he was ``extremely happy'' with the Government's U-turn.

``It's been announced for the ninth time. I must have faith in it,'' he said.

Cr Patterson said it was a ``critical piece of infrastructure'' with more than 250,000 new residents coming to the area over the next two to three decades.

An environmental assessment for the new plans is expected to go on public display in April next year.

``This Government will be judged on action and when I said I would start delivering, I meant it,'' he said.