Scott Morrison is offering almost $1.5 billion for navy ships, cyber security and public transport before he goes head-to-head debating Bill Shorten.

Both leaders are in Perth on Monday ahead of their evening debate, the first of the campaign, as a new poll shows the gap between them is narrowing.

The Australian’s Newspoll revealed Labor is leading the two-party preferred vote with just 51 per cent to the coalition’s 49 per cent.

The result is a marked improvement for the coalition since March, when Mr Morrison’s government was down 54-46 on the same measure.

But both parties will have to rely on preferences, with the coalition’s primary vote down to 38 per cent, and Labor down to 37 per cent.

The prime minister will visit Labor MP Josh Wilson’s electorate of Fremantle on Monday to announce a $1 billion plan to build three new naval vessels in Henderson.

“We’re backing the West with our commitment to make WA a home of continuous naval shipbuilding in Australia and the Henderson precinct is crucial to Australia’s defence capability,” Mr Morrison said.

He’s also promising $156 million to improve cyber security for older Australians, small businesses and national security assets.

A further $300 million will go to building or expanding 30 park-and-ride facilities on seven train lines in Melbourne.

“These projects will ease access to public transport, take thousands of cars off the road, bust congestion and see Melburnians spend less time in traffic and more time with their family and friends,” Treasurer Josh Frydenberg said.

Mr Shorten made his major policy announcements on Sunday, promising $1000 of free dental work for aged pensioners.

He also promised to make child care cheaper for almost one million families and a 20 per cent pay increase for early educators.

Monday’s debate will be the first between the two leaders, with a second scheduled for Friday in Brisbane.

The coalition is pushing for a third debate in prime time next week, but Mr Shorten wants it at lunch time from the National Press Club.

Coalition strategists believe putting Mr Shorten in the national spotlight without his key frontbenchers beside him will benefit Mr Morrison as they try to win over undecided voters.

The coalition leader has regularly tried to make the election contest a personal battle with Mr Shorten, who still trails as preferred prime minister in the polls.