Labor is leading the coalition in a Newspoll for the first time since Malcolm Turnbull became prime minister over six months ago.
The poll, published by The Australian on Monday night, shows Labor ahead by 51 per cent to 49 per cent in two-party preferred terms.
The poll, ahead of a possible double-dissolution election on July 2, shows the government's primary vote down two points in the past fortnight to 41 per cent and Labor's up two points to 36 per cent.
Mr Turnbull's personal approval rating has slipped one point to 38 per cent, while Labor leader Bill Shorten's rating is up four points to 32 per cent.
The poll was taken from Thursday to Sunday after Mr Turnbull floated the idea of giving states some income tax-raising powers, and amid perceived tensions between him and Treasurer Scott Morrison.
However, the latest Roy Morgan poll also released on Monday showed the coalition increasing its support on a two-party preferred basis by three points to 52.5 per cent, overtaking Labor which was down three points to 47.5 per cent.
