As Malcolm Turnbull’s increasingly shaky-looking government mobilises for a federal election campaign, it has particular cause for concern about the strength of its forces on its once formidable western flank.

An analysis of state-level polling trends, encompassing published breakdowns from Newspoll, Ipsos and Roy Morgan together with unpublished ones from ReachTEL and Essential Research, suggests Labor is finally about to bounce back in Western Australia after a decade of miserable electoral performances at both federal and state level.

Broadly speaking, the trend across the six states looks much the same, with the Coalition soaring to new heights in December from the depths of Tony Abbott’s terminal phase, only for the gloss to steadily fade with the onset of the new year.

However, the movements have been notably more moderate in New South Wales, which turned less aggressively against Abbott in the first instance, then shifted back more modestly under Turnbull, and has lately recorded a softer Labor recovery than most other states.

But the most significant variations in state-level polling since 2013 have their roots in the Abbott era, when support for the Coalition fell most heavily in what have recently been its two strongest states — Queensland and Western Australia.

In the west especially, the Liberals are coming off an unsustainable high, after winning 12 of the state’s 15 seats and scoring 58.3% of the two-party vote in 2013.

While two-party majorities for the federal Coalition are the historic norm in WA, this result came within an ace of matching 1975, when the only seat left to Labor was Fremantle.

A good deal has happened since then, little of which has been to the advantage of the Liberals.

While the halcyon days of the mining boom had clearly passed by the time of the 2013 election, the effects on the state’s economic vitality have since become increasingly hard to miss.

What was then a state unemployment rate of 4.5% has since climbed to 6.1%, overtaking a national rate that started and ended the period in question at around 5.8%.

Relatedly, a positive net migration flow that peaked at nearly 20,000 in the first quarter of 2012 has barely kept its head above water over the past two years.

As well as indicating the subdued state of the local economy, this figure also points to an exodus from the state of a largely conservative brand of voter who was drawn by the temporary opportunities of the mining boom.

Worse yet for the Liberals, voters now have much less reason to sheet home the blame for what ails them to Labor.

On top of the Coalition’s three years in power federally, Colin Barnett’s state government has held the reins for seven-and-a-half years, and has accumulated more than its fair share of baggage even for a government of such longevity.

While none of the Liberals’ WA seats are easy pickings for Labor, the accumulation of negatives should give any Liberal on a margin well inside single figures to feel nervous.

First in the firing line is Luke Simpkins, who gained the northern suburbs seat of Cowan for the Liberals against the trend in 2007, and watched his margin blow out to 7.5% amid the successive Labor disasters that followed.

A redistribution has now weakened Simpkins’ hold on his electorally volatile mortgage belt electorate, paring his margin back to 4.0% — inside the statewide swing pointed to by the poll aggregate.

Simpkins came to national attention last February when he moved the unsuccessful spill motion against Tony Abbott’s leadership, which appeared to say more about his sense of electoral security than his ideological dispositions.

He has otherwise been notable for his vigilance against the threat of Islam, having railed against halal food and nightclub logos that from a distance look a little bit like they might be jihadist symbols.

In the face of such competition — and in a seat that balances substantial migrant areas nearer the city with distinctly white-bread new suburbs on the metropolitan fringe — Labor has enlisted the services of self-described “secular Muslim” Anne Azza Aly, an Egyptian-born counter-terrorism academic and occasional guest on Q&A.

Elsewhere in Perth are two further seats where Liberal incumbents hold what look like solid margins after the blowouts of 2010 and 2013, but which have traditionally formed part of the marginal seat front line.

The eastern suburbs seat of Hasluck was won by Labor on its creation in 2001, and then changed hands at each of the next three elections.

Hasluck’s jinx for sitting members was broken in 2013 by Ken Wyatt, who had become the first indigenous person to be elected to the House of Representatives in 2010, but it would only take a reversion to the mean to put him in real trouble.

Similarly, the inner urban seat of Swan was held by Labor through most of the Howard years, suggesting Liberal member Steve Irons is considerably less secure than his 7.6% margin makes him appear.

Then there’s the new seat of Burt in the southern suburbs, created to give the state the 16th seat due to it after a decade of intensive population growth. Burt has a notional Liberal margin of 4.9%, but much of this bespeaks the famously strong personal vote of the late Don Randall in Canning, which encompasses the southern half of the area allocated to the new seat.

The swing to Labor at this end of Canning came in at around 10% at last September’s byelection — well above the overall result of 6.5%.

Labor’s candidate at the byelection, Matt Keogh, now has the opportunity to build on his hard work as the candidate for Burt.

Conversely, the Liberals are still tangled in a fraught preselection for the seat, in which a candidate favoured by most of the party establishment — Matt O’Sullivan, the chief operating officer of mining magnate Andrew Forrest’s indigenous employment scheme, GenerationOne — faces local councillor Liz Storer, who has backing from the party’s increasingly well-mobilised Christian right.

It’s not all bad news for the WA Liberals, who have a large contingent of senior ministers to boost their campaign firepower and face a Labor state branch that is undergoing a mass exodus of its remaining MPs.

However, if early counting on election night points to significant losses in the eastern states, Liberals with unsteady nerves will have no cause to relish the two-hour wait on the Perth marginals that could end up deciding the result.