Phoney election campaign well under way

The phoney election campaign appears to be well underway with the government and opposition trading barbs on key policies.

An energised Labor, buoyed by the latest Newspoll which shows them neck-and-neck with the government, sought to censure Prime Minister Malcolm Turnbull over his comment that changing capital gains tax was "no part of our thinking whatsoever".

Mr Turnbull retaliated, telling parliament a Labor government would "crash housing prices" through its plan to cap negative gearing and wind back CGT concessions on housing.

Opposition Leader Bill Shorten told the Labor caucus on Tuesday the government would attempt to "throw the kitchen sink" at the opposition before a possible double dissolution election in July.

However, a double dissolution election - in which the House of Representatives and all 76 Senators go to the polls - could now appear less alluring for the government.

Labor says it will oppose the Turnbull government's proposed changes to the Senate voting system, meaning the government will rely on Greens support on the Senate floor.

This legislation aims to ensure minor party candidates can no longer be elected on minuscule primary votes, ridding the Senate of its fractious crossbench which the government says has been obstructing its legislative program.

A double dissolution under the existing rules could mean an even larger crossbench.