Bill Shorten's popularity and standing as preferred prime minister has taken a hammering from voters, but Labor has kept its election-winning lead over the Turnbull government.

The findings, contained in September's Fairfax-Ipsos poll, show Labor has maintained the 53 per cent to 47 per cent lead in the two-party preferred vote it enjoyed in May, based on 2016 election preference flows.

If repeated on election day, there would be a 3.4 per cent swing away from the Turnbull government. If that movement was uniform, this would trigger a loss of 16 seats – which would comfortably hand power to the ALP given the government's slim one-seat majority.

But Labor strategists will be concerned at the big dip in voters' assessment of Mr Shorten's performance; approval of the Opposition Leader fell 6 percentage points since May, from 42 per cent to 36 per cent while his disapproval spiked from 47 per cent to 52 per cent, a statistically significant net 11 point shift.