After a rocky six-year marriage, and one near-split in 2016, the Coalition has come begging for forgiveness ahead of a date with electors in the divorce courts in May.

It's sorry about the incessant rows in the Liberal blue house, apologises profusely for the pots and pans flying angrily late into the night.

It knows that rent's been going up and up, and understands that turning on the lights, cooler and heater has become painfully expensive over the years.

It's very sorry indeed.

But before you pack your bags and shack up with the Laborite bloke in the red house called Bill, Scott Morrison's Coalition wants you to ponder this.

The rent's going to be slashed if you stick around with the Coalition, according to the PM's earnest emissary Josh Frydenberg. It's going to be around $1,080 lower for some individuals, $2,160 for couples.

How good's that, folks? See, we do care.

To take some of the power pain away, there's an Energy Assistance Payment, worth up to $125 for eligible couples. That doesn't entirely reverse the power price surge of the past six years, obviously. Electricity prices have increased 120 per cent over the past decade.

But it's a down payment, see, on a better life under the Coalition's roof. Scott and Josh promise it'll be better this time.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 25 seconds 1 m 25 s Leigh Sales questions Josh Frydenberg over Budget surplus figures

But that's not the end of the Budget pitch.

While the Coalition is offering a renovation of the blue house and promises more comfortable living inside, it's warning that the weather outside is turning for the worse. The economic winds are starting to buffet. Thank goodness the Coalition's gone for sturdy double-brick.

Why risk making the move to the red house, with its landlord's new-fangled ideas, taste for fancy climate change architecture and feel-good promises, the Coalition asks.

Bill Shorten might have made shifting home enticing, with his promises of even lower rents, electric cars and the like. But think of the overheads and the hidden costs! He's a spendthrift, don't you know? He comes from a long family of them, don't you know?

The Coalition says its superior household budgeting skills — what Mr Frydenberg says is its ability to make "difficult but necessary choices" — has allowed it to open the purse at this time of need.

Forget that the Chinese neighbour has been spending big on iron ore and coal supplied by the blue house at above-ordinary prices to keep his place in order.

The 2019 Budget is both a plea for forgiveness for the Coalition's years of infighting and an urgent call for electors to stick with what they know, rather than risk the known unknown.

Is it enough?

Bill Shorten's budget reply on Thursday will tell us whether he's at all rattled.