We strongly recommend two hours lessons.
Years of experience of driver training has told us that two-hour lessons are far more productive than just one hour, as more varied road types and topics can be covered, and repetition can take place to help consolidate learning.
Lesson content will also flow more consistently and seamlessly. As a result, a fewer number of lessons are normally needed overall to pass the driving test, which saves the pupil money.
However, if you find 2 hours are physically or mentally too demanding then discuss this with your instructor once allocated, as they may be willing to make an exception and offer you shorter lessons.