Construction on three new navy ships will be brought forward in Western Australia as the Coalition bids to save seats with the promise of defence spending and jobs.

The $1 billion investment will fund two minesweepers and a hydrographic vessel to be built in Perth in the mid-2020s.

The Coalition is banking on its record of ordering 34 new naval vessels and lifting defence spending to 2 per cent of gross domestic product to hold key WA seats.

Prime Minister Scott Morrison said bringing the ships’ construction forward from the 2030s would make sure there were no gaps in the pipeline of work.

“To maintain a sovereign defence industry, that continuity of build is critical,” Mr Morrison said at Civmec shipyard in Henderson, south of Perth, on Monday.

“To maintain what is enormous infrastructure and skills and support, you need that chain to be continually linked out into the future.

“This is about thousands of jobs in Western Australia.”

The $1 billion commitment will involved the replacement of the Huon-class mine hunters being brought forward from the 2030s to the mid-2020s.

A hydrographic military survey vessel will start construction in the early 2020s, also at Henderson.

Defence Industry Minister Linda Reynolds said the decision was made on the advice of the Defence Department.

Mr Morrison met ship building workers on Monday as he toured their facility in Labor MP Josh Wilson’s seat of Fremantle.

The Coalition needs to hold Attorney-General Christian Porter’s seat of Pearce, on a margin of 3.8 per cent, and Aged Care Minister Ken Wyatt’s seat of Hasluck, on a margin of 2.1 per cent.

But the Liberals are also targeting Labor MP Anne Aly’s seat of Cowan, which she holds by just 0.7 per cent.

The Prime Minister also announced $156 million to protect older Australians, businesses and national security assets from cyber attacks.

“[That’s] $80 million to put another 230 additional professionals, having them in our agencies, to combat the cyber security threats that Australia faces,” Mr Morrison said.

“There is $50 million that is going into a cyber security workforce strategy.”

A further $26 million will support businesses in dealing with their cyber security needs.

-AAP