The avoidance of tax by corporate executives and the very rich is the last thing the Turnbull Government needs as it prepares for a federal budget that is likely to be anchored by a cut in the company tax rate, writes Peter Lewis.

This week's Panama Papers data dump of one law firm's contribution to the global sport of tax avoidance looms as a wild card in the federal election.

The 2.6 terabytes of data implicating world leaders, major corporations and an estimated 800 high net worth Australians will generate a steady stream of revelations and possible prosecutions over the coming months.

The avoidance of tax by corporate executives and the very rich is the last thing the Turnbull Government needs as it prepares for a federal budget that is likely to be anchored by a cut in the company tax rate.

As I argued last week, the Turnbull Government's mishandling of its tax conversation was already pushing it into a corner where it is seen as governing for the top end of town rather than the broader public.

Not only will the PM likely enter a campaign justifying a tax cut while attacking Labor for tightening negative gearing concessions and paring back superannuation benefits for high income earners. But he will also now be called to explain why the Government has failed to act on homegrown tax avoidance and minimisation that sees a third of Australia's top companies paying no tax.

Meanwhile, his Government might be justifying reduced spending on health and education on the grounds that we do not have the money to meet public expectations.

If it was an election fought purely on competence, the incumbents would be in trouble. But findings in this week's Essential Report point to a more existential challenge for a Liberal Party currently in an arm wrestle between its conservative and small-l Liberal traditions.

We asked respondents to nominate which groups of society would be better off under a Liberal Government. The list is short and reads a little like the profile of the Mossack Fonseca client list.

Better off under a Liberal Better off under a Labor Makes no diff Don't know Difference Difference Sept 2015 Large corporations 50% 11% 22% 17% +39 +45 People and families on high incomes 49% 12% 23% 16% +37 +45 Banks and other financial institutions 47% 11% 24% 18% +36 +36 Families with children at private school 40% 16% 26% 18% +24 +36

There is a second cohort of groups where the difference between the major parties is less than 10 per cent. These include one-time Coalition strongholds of small business and farmers, as well as middle-income earners.

Better off under a Liberal Better off under a Labor Makes no diff Don't know Difference Difference Sept 2015 Small businesses 29% 24% 27% 19% +5 +12 Farmers and other agricultural producers 22% 23% 32% 23% -1 +5 People and families on middle incomes 24% 30% 30% 16% -6 -6

The common thread running through these groups is that these are not the people likely to be benefiting from the tax policies and non-policies of the current Government.

And then there is what seems to be a growing array of groups that people see as being part of the Labor heartland, otherwise know as everyone else.

Better off under a Liberal Better off under a Labor Makes no diff Don't know Difference (Liberal minus Labor) Difference Sept 2015 Pensioners 16% 36% 30% 17% -20 -23 Recent immigrants to Australia 12% 33% 32% 23% -21 -16 People with disabilities 15% 36% 32% 17% -21 -24 Average working people 17% 38% 28% 17% -21 -20 Unemployed people 12% 38% 31% 18% -26 -32 Single parents 12% 39% 30% 19% -27 -31 Families with children at public school 14% 41% 28% 17% -27 -23 People and families on low incomes 13% 42% 28% 16% -29 -33

With the parties locked at 50-50 in two-party preferred polls the risk for the Coalition is that after two years of Abbott and a muddled six months of Turnbull their constituency is shrinking before their eyes.

And after decades of falling victim to shrewd Coalition wedge attacks on everything from immigration to climate change, Labor has a chance to unify as a coalition those without the wit or will to beat the taxman.

Peter Lewis is a director of Essential Media Communications (EMC), a public affairs and research company specialising in campaigning for progressive social and political organisations. He tweets at @PeterLewisEMC.