Despite defeating mining magnate Andrew Forrest in a contest of political influence last week, the Minerals Council is shrinking as its members look to reduce their spending amid weaker commodity prices.

Recently published financial accounts for the lobby group show that revenues have slipped by 68 per cent between 2010 and 2014, despite the Minerals Council absorbing smaller industry groups like the Australian Coal Association and the Australian Uranium Association over that period.

Receipts from members topped $37.47 million during the height of the war against the carbon and mining taxes in 2010, but tallied just $15.63 million in 2014.

The most striking change over that period has been the council's advertising spend, which was $15.78 million in 2011, but just $1.67 million in the election year of 2013 and a mere $60,541 in 2014.

With the fate of the carbon and mining taxes clear by December 2013, the council decided to plunder $2 million from its long-term savings fund to reduce annual fees for members, and the recently published accounts suggest the same tactic is being deployed again.

"The council determined in December 2014 to gradually reduce accumulated funds by lowering annual subscriptions, with the financial situation to be monitored and subscription levels evaluated each year," the council said in documents submitted to ASIC last month.

Total assets and cash equivalents are now at lower levels than in 2011.

The Minerals Council represents more than 100 miners, including major miners such as  BHP Billiton, Rio Tinto, Peabody, Glencore, Anglo American and Newcrest Mining.

It does not count Fortescue Metals Group as a member, and vigorously fought Mr Forrest's campaign for a parliamentary inquiry into the iron ore industry.