The ACTU is recasting its political strategy after its own survey revealed a 10 per cent jump in the number of union members who are undecided about who they will support at next year's election.

A report prepared for the ACTU executive concedes the switch from Tony Abbott to Malcolm Turnbull has had an impact on its campaign strategy that is "yet to settle down".

The Liberal Party's switch to Malcolm Turnbull has resulted in an increase in undecided voters heading into next year's election, according to an ACTU survey. Credit:Christopher Pearce

The union movement's new strategy will seek to claim credit for any policy softening by Mr Turnbull and target soft Labor and Green supporters, the paper says.

"Our campaign has always been about defeating an agenda that was attacking our living standards and putting in place the foundations to improve living standards," says the report, obtained by Fairfax Media.