Premier Mike Baird and Health Minister Jillian Skinner toured the completed first phase upgrade of the hospital in the western Sydney battleground on Saturday and promised further expansion to cope with the growing population.

Funding for the redevelopment is contingent on the partial privatisation of the state's electricity network, a contentious plan the Baird government hopes will raise $13 billion for priority infrastructure projects.

Mr Baird would not commit to a specific time frame for works to start, saying "the planning will determine the final phasing", but the government was committed to it starting in the next term "and then [to be] completed over the following few years".

Emergency department waiting times at the hospital are among the worst in the state but during the election campaign both major parties have committed additional resources.

Opposition Leader Luke Foley has promised a $100 million paediatric surgical centre at the hospital if Labor is elected on March 28.

Labor says it can fund the commitment without selling the state's electricity network.

"It is only our government that has the capacity to fund this expansion," Mr Baird said. "It is only our government that will do it."

Mr Baird, who will unveil his full suite of policies at the Liberal Party's campaign launch on Sunday, said it would be a "close election, it's going to be a tough election".

"We have to fight every day. You can see for yourselves the negative campaigns that are running against us," he said, in a reference to Labor's anti-power privatisation advertisements. "Every single seat is a battle and we'll be taking it up."

The Liberal member for Campbelltown, Brian Doyle, joined Mr Baird and Mrs Skinner at the announcement.

The former chief inspector at Campbelltown Police and first-term MP holds the seat by a 6.8 per cent margin following a boundary change in 2013 which increased his advantage from 3.4 per cent.

Boundary changes have increased the lead of his colleague Jai Rowell, the Liberal member for the seat of Wollondilly, including parts of Campbelltown, from a 14.7 per cent margin to 21.6 per cent.

Mr Rowell, who was notably absent from the announcement, was "out door-knocking, as he should be", Mr Baird said.

"We are in the midst of an election campaign, there are many votes that we obviously want to win but more importantly we want to tell our local communities everything possible about what we are doing."

Mrs Skinner said stage two of the hospital expansion would involve new "operating theatres, a new emergency department, expanded clinics, and generally taking this hospital to the point where it will cope with growing demand".

Mr Baird conceded the policy depended on the sale of the electricity network.

"We are seeking a mandate for that and if we have the opportunity and privilege to continue in government beyond next week we will do everything we possibly can to not only do what we've announced but possibly more," Mr Baird said.

Shadow health minister Walt Secord said the plan was an attempt to "blackmail" local residents into voting for the sale of the electricity network.

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