Support for Bill Shorten has dropped to its lowest level since he became Opposition Leader, a new poll shows.

In the latest Essential poll, 52 per cent of voters disapproved of the job Mr Shorten was doing, which was up seven per cent on June.

Prime Minster Tony Abbott’s approval rating was also down, but still 10 points higher than Mr Shorten’s, Sky News reported.

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Looking at the net approval numbers, Mr Shorten was now behind the PM on minus 25 per cent.

Mr Abbott is at minus 16 per cent.

Mr Abbott retains his hold on the preferred PM rating, with 37 per cent of people saying he would make the better prime minister, while Mr Shorten garnered just 30 per cent,  Sky News reported.

On the primary vote, the Coalition maintained its lead with 41 per cent. Labor dropped one per cent, with 38 per cent of the votes.

In terms of two-party preferred, Labor still leads the Coalition 52-48, unchanged since June.

On Monday, a Roy Morgan poll revealed support for Mr Shorten had fallen following his appearance last week at the Royal Commission into unions.