Independent senator Glenn Lazarus believes the Turnbull government's chances of winning the next election are diminishing.
"I think Malcolm Turnbull and his government's popularity is waning at a rapid rate," he told ABC TV.
Senator Lazarus said the government was focused on the building and construction watchdog at a time when Australians wanted other issues addressed such as the cost of living, Gonski school funding and cuts to services.
Senator Lazarus said everybody had high hopes for Mr Turnbull when he took over from Tony Abbott but he has been disappointing.
Family First senator Bob Day said there was "no such thing as an unlosable election".
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The government's legislation to change the way Australians vote for senators could backfire, he said.
"It's upset an awful lot of minor parties and independents who are pretty cranky about it and could well preference against the government in a lot of key seats," he told ABC TV.
Mr Turnbull has threatened a July 2 double-dissolution election should the Senate fail to pass the ABCC and registered organisations legislation.
Since making that threat opinion polls have turned against the government.
Liberal Democratic senator David Leyonhjelm believes the only thing that will stop a double dissolution is if opinion polls between now and the May 11 - when such an election has to be called - show that Mr Turnbull is going to lose.
"It's become a matter of whether you would rather lose an election or look ridiculous," Senator Leyonhjelm told Sky News.
"I think I would rather look ridiculous than lose an election."
