On the final day of an extraordinary two-week parliamentary session that had been scheduled for the precise purpose of removing both taxes from the statute books, the Senate blocked removal of the mining tax unless billions of dollars worth of spending on benefits to families and low-income earners was retained.

Shell-shocked Coalition MPs and senators expressed exasperation that Labor, the Greens and the Senate crossbench had apparently not acted in the national interest.

Treasurer Joe Hockey said failure to repeal the tax meant $17 billion, or about $13 billion net, in unfunded spending through to 2017-18 would go ahead, including the Schoolkids Bonus, the income support bonus, the low-income superannuation bonus and a range of other measures, had been locked in by the Senate's blocking vote.

Mining companies will now have to pay the next instalment of the tax, which is due on July 21.

''The government cannot afford to keep borrowing money to pay for this kind of unfunded spending,'' Mr Hockey said.

''Labor voted to keep every dollar of unfunded spending linked to the mining tax, and then voted to keep the failed tax.

''Labor should immediately outline how it will fund all of the spending linked to the mining tax. The government will not accept amendments which support these unfunded spending measures remaining in place.''

Labor Treasury spokesman Chris Bowen and Families spokeswoman Jenny Macklin hailed the Senate's move to save the spending on families, as did Greens leader Christine Milne.

Minerals Council chief executive Brendan Pearson said the imperative to repeal the tax remained and that until repealed, the tax would act as a ''drag on industry confidence and significant compliance burden''.

Clive Palmer's fledgling balance-of-power party was central to the Senate blockage, which has delivered another blow to the government's budget repair schedule.

The government was blindsided as PUP senators again refused to bow to its demands on Friday and voted with Labor and the Greens to keep the amendments and thus leave the tax in place for now.

An analysis by the Australia Institute - a left-leaning think tank that has been advising the Palmer United Party - has found that savings nominated in the budget but blocked by PUP, combined with the opposition and Greens, amount to $13.02 billion over four years while helping to save thousands in payments to some low-income families.

The analysis concluded that, for a family with two adults working for the minimum wage with three school-age children, the saving could approach $3800 a year.