Govt rejects Labor's subs tender changes

The Abbott government believes it is saving Labor from itself in rejecting a call for a competitive tender for Australia's next submarine fleet.

The opposition has used an unrelated bill to legislate its demand for a tender, a parliamentary tactic popular in the US Congress but not seen as often in Australia.

The amended legislation returned to the lower house from the Senate on Wednesday for approval, but the government promptly rejected it as unreasonable.

Parliamentary secretary Christian Porter said he was protecting the opposition because if it got its way, there would be a further five-year wait for new submarines.

Besides, submarines had nothing to do with a bill about repealing minor regulations.

"It's patently absurd," Mr Porter told parliament.

Labor frontbencher Mark Butler said the government was trying to defeat the will of the Senate, where the bill will be now returned.