THE Coalition is facing the unthinkable as its leader and his deputy confront serious harm to their authority and the Government.

Prime Minister Scott Morrison needs a convincing Liberal win in Saturday’s Wentworth by-election to repair damage from an extraordinary accumulation of political stumbles over just seven weeks.

There is a growing possibility he might be denied that respite — a final snub from the former member for the seat Malcolm Turnbull, who will watch the ballot count with son Alex in Singapore.

The worst result for the Liberals — a loss to an independent or Labor — would cost the Government its one-seat majority and likely put at risk Mr Morrison’s prime ministership.

Adding to the uncertainty, Nationals leader and Deputy Prime Minister Michael McCormack is on notice from predecessor Barnaby Joyce who has it made clear in public he is back on the leadership market.

The idea of a second top level Nationals’ turnover in roughly 12 months would ruin the party’s ability to mock Liberal instability and invite voter rejection.

It could be a comeback angering a significant number of voters, particularly women, who might see a leadership switch as Mr Joyce escaping accountability for bad private behaviour.

The woes have an added dimension given the start of 2019 will in effect begin the election campaign — federally and in Mr Morrison’s home state of NSW.

The Government needs to implant positive views in the minds of voters before Parliament rises for summer in early December. If not, voters will take negative opinions of the Government into the holiday period, and return to them in the new year.

The distinctive nature of the Government’s problems is they have been creatures of its own creation.

The Labor Opposition has underlined the political mishaps but otherwise has been a mere spectator to them.

The latest self-inflicted injury occupying the Government comes from the Tuesday night comments in a Canberra restaurant attributed to new Environment Minister Melissa Price.

Ms Price has denied the comments 100 per cent, but at least two witnesses have contradicted her.

They say she approached the former president of Kiribati, Anote Tong, in Australia to raise awareness of the danger of rising sea levels to Pacific Islands.

Her remarks have been said to show limited empathy: “I know why you’re here. It is for the cash.

“For the Pacific, it is always about the cash. I have my chequebook here. How much do you want?”

But this has been just one episode.

It joins, in this week alone, concerted and senior medical protests over the treatment of asylum seeker children stranded on Nauru.

It was an administrative error which saw Government senators accidentally back a One Nation stunt — an abrupt announcement Australia will consider moving its Israeli embassy to Jerusalem, disturbing our most important neighbour, Indonesia