A new poll shows the Barnett government would lose one of its crucial Perth seats with a nearly 20% swing against the sitting MP.

It could spell major trouble for Colin Barnett’s bid for a third term as premier at the 11 March election as Labor needs a uniform swing of 10% to gain the nine seats it needs to win.

The ReachTell poll of 700 residents in the seat of Joondalup, commissioned by Labor, found the ALP leading 58%-42% on a two-party preferred basis, the West Australian newspaper reported.

That’s a swing of 18.1% against sitting MP Jan Norberger since the 2013 election. On the primary vote, Labor leads 35.2%, with the Liberals trailing on 32.6%. One Nation is polling 13.7% on the primary vote for the seat and the Greens are on 10.2%.

Pauline Hanson last week sacked her candidate for Joondalup, Brian Brightman, after he revealed a 23-year-old conviction for theft of $1,100 worth of departure tax stamps when he was a customs officer at Perth airport.

A Liberal party room meeting will be held later on Tuesday where Barnett and his deputy Liza Harvey will outline the strategy for the election campaign which will officially get under way with the issuing of writs on Wednesday.