Shorten to address party faithful

Bill Shorten will kick off the final two weeks of a gruelling election trail with an address to the party faithful at Labor's official campaign launch.

With both major parties regarding western Sydney as a key battleground of the election, the Labor clan will fittingly gather in Penrith on Sunday.

Mr Shorten will thank the party for putting its faith in him to restore the Labor brand after the six turbulent Rudd-Gillard-Rudd years in government.

He will drum home Labor's plans to boost jobs, the need to protect Medicare and to properly fund mental health care.

He will also promote Labor's support for working parents through greater accessibility to child care, while attacking the government's cuts to schools, hospitals and family benefits.

Under Mr Shorten's leadership, Labor has gone from also-rans after Malcolm Turnbull became prime minister last September, to within a fighting chance for the July 2 election as opinion polls show the opposition having a slight advantage.

However, it could all be in vain with polling also showing Labor failing to pick up enough support in key marginal seats to take the 21 seats needed to govern in its own right.

Mr Shorten visited the NSW Central Coast on Saturday to unveil a $300 million five-point plan to tackle chronic disease.