Malcolm Turnbull's Senate voting reforms made voting more difficult, many voters say. And Julie Bishop is firming as the preferred leader of the Liberal Party, behind a diminished Turnbull, new polling from Essential Research reveals.

After Senate voting changes designed to make voting easier and reduce the role of preference deals failed to reduce the size of ballot papers in many states, 37% of voters say the changes made voting more difficult while 25% said it made no difference. Less than 20% said the changes made voting easier.