The Leader of the Opposition Bill Shorten emphasised fairness and fiscal discipline in his budget reply last night, claiming over $70 billion in new savings while attacking Malcolm Turnbull for his links to business.

The bulk of the savings will come from Labor’s refusal to support the government’s planned big business tax cut over the next decade, which he said Labor modelling commissioned from the Parliamentary Budget Office suggested would cost $49 billion.

The issue dominated politics yesterday, with the government refusing to provide an estimate of the cost. The Prime Minister stumbled badly over the issue in a poor interview with Sky News’ David Speers, who pressed and pressed Turnbull on the issue; Treasurer Scott Morrison was similarly hammered by Neil Mitchell on Melbourne radio and struggled to answer. Treasury this morning revealed that its costing was $48.2 billion.

Shorten also unveiled a $6 billion saving over ten years from cutting funding to the scandal-plagued private vocational training sector, and committed Labor to retaining the “temporary” deficit repair levy instituted by the Abbott government, garnering another $16 billion.

However, Labor will oppose the retrospective elements of the government’s hard-hitting superannuation tax concession changes, losing some of the $4.4 billion in savings the government will bank of the next four years. That decision creates the bizarre contrast of the Coalition promising retrospective cuts to super tax concessions, which are deeply unpopular with the super sector and the Liberal party base, while Labor is opposing them — and it’s all the more bizarre given it was Labor’s commitment to cuts to super tax concessions that drove the government to embrace them in the first place. Expect this issue to continue to play out across the campaign.

Shorten mocked the government’s mechanism for transitioning to a lower company tax rate for all companies, not just small businesses, by lifting the threshold at which it applied. Companies with a turnover of a billion dollars could never be small businesses, he said, mentioning Coles and the Commonwealth Bank, before adding “Goldman Sachs isn’t a small business”.

Beyond Labor’s claimed $71 billion in savings over a decade, there was little detail on new spending. Two key areas of policy vagueness remain: Labor hasn’t made clear what its approach will be to the NBN — all Shorten said was that Labor was committed to “a first-rate, fibre, National Broadband Network.” Nor was there any detail about how much additional funding Labor would provide the states for health beyond that promised by the government as part of its recent effort to shut down the controversy over Tony Abbott’s $80 billion cuts to health and education funding. Noticeably, too, Shorten did not commit to restore the $1.2 billion in aged care funding cut on Tuesday night.

Shorten’s speech itself was delivered in the more relaxed and more confident manner the opposition leader has managed in recent weeks, and interrupted repeatedly by applause from the Labor supporters packed into the public galleries (especially for his commitment to legislate marriage equality). The most peculiar aspect of the evening, however, is that it sets up the July 2 election that will be based almost entirely on issues of policy substance, most of them driven by an opposition that has gone hard on policy and dragged a reluctant government with it. The result is likely to be the most policy-focused election in years. It’s what voters say they want from politics, but whether it engages them over the coming eight weeks remains to be seen.