Sydney's current metropolitan strategy was released five years ago. It remains a pretty good document.

The 2005 strategy proposed that Sydney's growth should shift away from endless new suburbs on the fringe and instead build Sydney into a city of cities.

Of course, the Sydney CBD would remain Sydney's foremost centre. Away from the CBD, however, Parramatta, Penrith and Liverpool were nominated as regional cities.

These regional cities were slated to grow as major commercial, retailing and employment centres. And their growth was to be assisted by investments in new infrastructure.

By building a city of cities, according to the 2005 strategy, Sydney's sprawl could be limited. New dwellings could be built in well-designed medium density precincts in and around the regional cities, and along transport corridors, and so reduce car use.

Many of Sydney's current problems -- congestion, jobs in the wrong places, high housing costs -- are now entrenched because the 2005 strategy was never properly funded and never fully implemented.

The big loser has been Western Sydney and its three struggling regional cities.

Yet Western Sydney is called on in the government's new discussion paper to do the heavy lifting as Sydney grows to 6 million people by 2036. Two thirds of the extra 1.7 million people are pencilled in for Western Sydney.

So too, Western Sydney is expected to do the lion's share of absorbing new migrants.

Western Sydney will also be asked to host most of Sydney's new medium density dwellings.

At present, 80 per cent of full-time workers from Western Sydney are forced into their cars to get to work.

And over 30 per cent of Western Sydney workers are forced to travel beyond their region each day to find work.

A revised metropolitan strategy presents the NSW government with the opportunity to build a fairer, more sustainable city for all Sydneysiders.

But the government's efforts, and its funding, must be directed first and foremost at building Western Sydney's regional cities, growing the region's jobs base and fitting out the west with quality infrastructure, especially public transport infrastructure.

Anything less will make the revised metropolitan strategy look like a sham.

Phillip O'Neill is Professor and Director, Urban Research Centre, The University of Western Sydney.