Exploding insurance premiums has prompted Senator Nick Xenophon to call for an inquiry into ways to inject fresh competition into the market.

Senator Nick Xenophon will today put a motion to the Upper House for an economic references committee inquiry into whether there is a need to inject competition into the $28 billion-a-year car, home and strata insurance markets by setting up an independent comparison service — a proposal first raised by News Corp Australia.

Labor, the Greens and Jacqui Lambie have told News Corp Australia they will support the motion, meaning it will pass with at least 39 of the maximum 76 votes that can be cast.

It is a nightmare outcome for Big Insurance, which believed it had contained the people-power push for policy price relief.

Now it will have to explain why the cost of protecting a home has increased at nine times the rate of earnings in the past four years — and justify its view that it is a bad idea to make it easier for consumers to find better value via a one-stop cybershop.

Currently a consumer wanting to size up the market would have to enter the same data into as many as 10 websites because there is no comprehensive insurance comparison service. Brands controlled by the four largest insurers don’t participate in private-sector aggregators, which are left to evaluate less than 30 per cent of the market. The independence of aggregators has also been called into question because some are owned by insurers.

“Insurance companies ganging up against consumers to present flimsy comparisons of policies needs to be exposed,” said the Greens’ Finance spokeswoman Senator Sarah Hanson-Young.

“This type of underhanded behaviour shouldn’t be allowed to masquerade as supporting consumer power, it is anything but.

“The Greens believe it’s time to explore a fairer system and scrutinise how insurance companies structure their fees to make sure Australians have all the information and are not being ripped off.”.

Ms Lambie will ask the committee to look at forcing insurance brokers to prove they disclosed policy limitations to clients after some businesses in her home state of Tasmania were unable to make claims for flood damage.

“Brokers and insurance companies should be dragged across the bloody coals,” Ms Lambie said.

About 6000 people have signed petitions seeking a comprehensive, independent insurance comparator. Most of them have done so while joining the Big Insurance Switch, which is seeking a group-discount on home and car insurance and supports the push for an independent comparison service.

To sign the petition and for more information on the Big Insurance Switch go to www.onebigswitch.com.au

There is no obligation to take up any offer. News Corp Australia and One Big Switch will earn a commission from any accepted deals. News Corp is a shareholder of One Big Switch.