Second reading is the first opportunity for MPs or Lords to debate a Private Bill which they oppose. Unopposed Bills proceed without debate
Unopposed Private Bills
If a Private Bill is not opposed by an MP or Lord at the time of its second reading, the second reading is complete once the Clerk has read out the title of the Bill. The Bill then moves on to its committee stage.
Opposed Private Bills
Any MP or Lord may oppose a Private Bill at second reading. If a Private Bill is opposed at second reading, time must be found on the floor of the House to debate it. Debates on Private Bills at second reading tend to be wide-ranging, often including discussion on the general subject of the Bill as well as its specific merits.
As with Unopposed Private Bills, once the Bill has had its second reading, it moves on to committee stage.