The pay deal, agreed to last week and backdated to March, also hands a three-year, 8.5 per cent pay rise to workers at the company's Claremont factory that is broadly in line with inflation.

Fairfax Media revealed in February that Cadbury workers' enterprise bargaining agreement contained generous allowances that were comparable, or even better than, workers at the SPC Ardmona cannery in Shepparton.

Mr Abbott pledged $16 million to Cadbury to upgrade tourism infrastructure during last year's election.

But his government knocked back a request for $25 million in assistance from SPC, citing overly generous ''wet'' allowances for workers, redundancy provisions and the ability to cash out sick leave – which Cadbury workers can also do in some circumstances.

The Prime Minister has repeatedly dismissed suggestions the two cases are similar, arguing the Cadbury money is for tourism while the SPC money would have been for ordinary operations.

The Australian Manufacturers Workers Union, which represents workers at SPC and Cadbury, said workers at both companies earned about $50,00 annually, though pay rates varied according to shift times and loadings.

The AMWU Tasmanian secretary John Short said workers had taken a lower pay rise than they had done previously, and instead negotiated for an increase in permanent jobs and further training.

''This has led to many casuals having the opportunity to get stable, permanent employment at Cadburys,'' he said.

Cadbury Director Simon Talbot said it would be ''naive'' not recognise the money being handed to his company was tourism infrastructure.

''Manufacturing operations and wage conditions are completely separate and in no way related,'' he said.

Austrade CEO Bruce Gosper, who heads up the organisation charged with handing out the $16 million payment, told a Senate estimates hearing that no business plan had yet been presented by Cadbury.

Mr Talbot said the company was developing the business case for the money that had already been promised by the government.