I've not the strong answer, but I have an opinion.
If I draw the diagram of a transformer, and try to find-out the direction of current using Lenz's law; if I keep the coiling-pattern of primary and secondary coils Same (Say both as righthand-screw, or both as Lefthand-screw); I'm getting an 'opposite', i.e. 180-degrees phase-shifted currents in the 2 coils.
However I do-not know, in which-way Lenz's law acts in transformer; because the law states the induced current will try to hinder the cause. but when the secondary circuit of a step-up transformer turned On (closed) , so-far I've know , the current in primary-coil goes-up
In-fact I was going to ask a question about whether a transformer cause any phase difference. But I found already someone asked such a question here, already mentioning 180 degrees phase shift. So I've added my- thoughts here.
Any feedback is welcome.